UC-NRLF 


B    3    135    MD1 


STUDENTS  IN  GENERAL  CHEMISTRY 


\ND      KELLER. 


REESE  LIBRARY 


UNIVERSITY  OF  CALIFORNIA, 


EXPERIMENTS 


ARRANGED    FOR 


STUDENTS  IN  GENERAL  CHEMISTRY 


EDGAR  F.  SMITH,      AND     HARRY  F.  KELLER, 

PROFESSOR    OF   CHEMISTRY,    UNIVERSITY    OF  PROFESSOR    OF   CHEMISTRY,    CENTRAL    HIGH 

PENNSYLVANIA.  SCHOOL   OF    PHILADELPHIA. 


THIRD  EDITION,  ENLARGED,  WITH  41    ILLUSTRATIONS. 


UNIVERSITY 


PHILADELPHIA: 
P.    BLAKISTON,    SON    &    CO 

IOI2  WALNUT  STREET. 
1895. 


COPYRIGHT,  1895,  BY  P.  BLAKISTON,  SON  &  Co. 


PRESS  OF  WM.   F.   FELL  &  CO., 

1320-24   SANSOM    ST., 

PHILADELPHIA. 


PREFACE  TO  THE  THIRD  EDITION. 


This  little  work  is  designed  as  a  guide  for  beginners  in 
chemistry.  The  authors  have  found  the  course  of  instruction 
as  arranged  in  the  following  pages  productive  of  good ;  its 
object  is  not  to  dispense  with  the  supervision  of  an  instructor, 
but  rather  to  assist  him. 

The  present  edition  differs  fron*  its  predecessors  in  the  fol- 
lowing points  :  many  new  experiments  and  new  illustrations 
have  been  introduced,  while  not  a  few  of  the  experiments 
described  in  former  editions  have  been  modified  in  accord- 
ance with  the  experience  obtained  in  the  daily  use  of  the 
book  with  large  classes.  The  text,  too,  has  been  subjected  to 
careful  revision. 

Although  reference  is  frequently  made  to  Richter's  "In- 
organic Chemistry,"  fourth  edition,  any  other  text-book  on 
the  subject  can  be  employed  in  its  stead.  The  experiments 
have  been  collected  from  various  sources,  and  no  claim  is 
made  for  originality. 


€:V°ERSITY) 
CF  "x 


in 


CONTENTS. 


NON-METALS. 

CHAPTER  PAGE 

I.  APPARATUS,  MANIPULATIONS  AND  OPERATIONS, 9-10 

II.  GENERAL  PRINCIPLES, 11-12 

III.  HYDROGEN, 13-17 

IV.  CHLORINE,  BROMINE,  IODINE,  FLUORINE, 17-25 

V.  OXYGEN,  SULPHUR, 25-35 

VI.  NITROGEN,  PHOSPHORUS,  ARSENIC,  ANTIMONY, 36-45 

VII.  CARBON  AND  SILICON,  BORON, 46-50 

METALS. 

VIII.  POTASSIUM,  SODIUM  [AMMONIUM],     51-58 

IX.  CALCIUM,  STRONTIUM,  BARIUM, 58-60 

X.  MAGNESIUM,  ZINC,     60-63 

XI.  MERCURY,  COPPER,  SILVER,  GOLD, 63-69 

XII.  ALUMINIUM,  TIN,  LEAD,  BISMUTH,     69-73 

XIII.  CHROMIUM,  MANGANESE,  IRON,  NICKEL,  COBALT,    .    .    .   .74-83 

XIV.  PLATINUM, 83-84 

APPENDIX, 85-86 


NON-METALS. 


FIG.  i. 


CHAPTER    I. 
APPARATUS,  MANIPULATIONS  AND  OPERATIONS. 

(1)  The  Bunsen  Burner  and  the  Blowpipe. 

i.  Make  a  borax  bead.  2.  Dissolve  a  very  minute  quantity 
of  manganese  dioxide  in  it.  3.  Heat  in  the  oxidizing  flame  (?). 
4.  In  the  reducing  flame  (?).  5.  Heat  oxide  of  lead  on 
charcoal  in  the  reducing  flame.  6.  In  the  oxidizing  flame. 

(2)  Working  with  Glass  Tubing  and  Rods. 
i .   Cut  various  lengths  of  rods  and  tubing. 

2.  Round  the  sharp  edges  by  softening  and 
turning  the  ends  in  the  lamp. 

(3)  Construct  a  Wash  bottle  (Fig.  i). 

i.   Soften    a   sound    cork    by   rolling    it 
under  your  foot  on  a  clean   floor.     2.  Bore 
two   parallel  holes  through  it  by  means  of 
a  cork-borer.    These  perforations  should  be 
cylindrical  and  of  less  diameter  than  the 
glass  tubes  they  are  to  receive.     Use  a  rat- 
tail  file  in  enlarging  them.     3.  Cut  suitable 
lengths  of  glass  tubing.     4.  Draw  the  longer  one  to  a  fine 
point  after  softening  in  the  flame.     5.  Bend  the  tubes  in  an 
ordinary  fish-tail  burner,  and  round  the  sharp  edges.     6.  Fit 
the  different  pieces  together. 

(4)  Arrange  some  other  form  of  apparatus  for  practice. 

(5)  The  Balance. 

9 


10  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

i.  Weigh  an  object  by  placing  it  on  the  left-hand  pan  of 
the  balance,  and  a  weight  judged  about  equal  on  the  right- 
hand  pan.  Should  the  latter  be  found  too  heavy,  replace  it 
by  the  next  smaller  one ;  if  too  light,  by  the  next  heavier 
one.  Then  add  systematically  the  smaller  weights,  until  the 
needle  points  to  the  middle  of  the  scale.  The  final  adjust- 
ment is  made  with  the  rider.  In  adding  or  removing  weights, 
the  supports  must  always  be  raised. 

(6)  Measuring  Vessels. 

i.  Measure  off  10  cc.  of  water  (a)  in  a  cylinder,  (£)  in  a 
burette,  (V)  in  a  pipette.  Always  read  the  lower  meniscus. 
2.  Measure  off  similarly  50,  100  and  200  cc.  of  water,  and 
determine  their  weight.  3.  Measure  the  volume  of  50  grams 
of  oil  of  vitriol,  and  of  65  grams  of  muriatic  acid.  What  are 
the  specific  gravities  of  these  substances  ?  Note  the  relation 
between  weight  and  volume  in  the  metric  system. 

(7)  Chemical  Operations. — Solution,  evaporation,  crystalli- 
zation, precipitation,  filtration,  washing,  and  drying. 

i.  Place  into  a  test-tube  pure  sodium  carbonate,  into  an- 
other cobalt  chloride,  and  add  distilled  water  to  each.  Stir. 
What  occurs?  2.  To  calcium  carbonate,  add  water.  Is  there 
any  change?  Now  add  a  little  hydrochloric  acid.  What 
action  has  it?  3.  Pour  five  cc.  of  strong  hydrochloric  acid 
upon  powdered  manganese  dioxide  ;  observe  appearance  and 
odor.  Note,  too,  in  each  case,  whether  heat  has  any  effect. 
Distinguish  between  chemical  and  mechanical  solution.  4. 
Heat  the  cobalt  chloride  and  the  calcium  carbonate  solutions, 
each  in  a  separate  dish,  on  an  iron  plate,  until  the  liquids  are 
completely  driven  off  (?).  5.  Dissolve  potassium  chlorate  in 
hot  water,  and  allow  to  stand  and  cool  (?).  6.  To  a  portion 
of  the  cobalt  chloride  solution,  add  a  solution  of  soda ;  boil. 
7.  Allow  to  settle  and  filter.  8.  Wash  the  precipitate  until 
pure  water  runs  through  the  filter  (?).  9.  Heat  the  filter  until 
perfectly  dry. 


GENERAL    PRINCIPLES.  II 


UNIVERSITY 
CHAPTER   II": 


GENERAL  PRINCIPLES. 

(i)   Changes  in  Matter. 

i.  Rub  a  glass  rod  with  a  piece  of  cloth,  then  touch  parti- 
cles of  paper  with  it  (?).  2.  Through  an  insulated  spiral  of 
stout  copper  wire  pass  a  current  from  two  Bunsen  cells.  Place 
a  piece  of  wrought  iron — a  nail  will  answer — inside  the  spiral, 
and  bring  iron  filings  in  contact  with  it.  What  happens? 
Interrupt  the  current  and  note  the  result;  repeat.  3.  Heat 
a  platinum  wire  in  the  non-luminous  flame ;  is  there  any 
change  ?  What  is  the  effect  of  removing  it  ? 

Are  the  original  properties  of  the  substances  in  the  above 
experiments  altered,  after  the  action  of  the  forces  of  electric- 
ity, magnetism  and  heat  has  been  stopped  ? 

4.   Mix  intimately  four  parts,  by  weight,  of  finely  powdered 
sulphifr  with  seven  parts  of  very  finely  divided  iron  (filings). 
Pass  a  magnet  over  a  portion  of  the  mixture.     Another  portion 
treat  with  carbon  disulphide  in  a  test-tube.     Then  heat  the 
remaining  portion   in  a  tube   over  a  gas-flame. 
Note  carefully  what  occurs  in  each  case.     Powder       F*G. 
the  mass  resulting  from  the  last  operation  in  a  dry 
mortar.     Can  you  extract  from  it  any  iron  with  a 
magnet,  or  dissolve  out  any  sulphur  with  carbon 
disulphide?     What  inference  do  you  draw  from 
the  facts  observed  ?    5.  Decompose  water  in  Hof- 
mann's  apparatus  by  an   electric  current.      The 
water  should  be  acidulated  with  sulphuric  acid  to 
make  it  a  conductor  of  electricity.     A  current  from  four  to 
six  Bunsen  cells  is  required.     To  the  gas,  of  which  a  larger 
volume  has  collected,  apply  a  flame,  and  to  the  other  a  glow- 
ing spark  at  the  end  of  a  chip  of  wood  (?)     6.   Heat  oxide  of 


12  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

mercury  in  a  tube  of  hard  glass  (Fig.  2.)(?)  7.  Grind  sul- 
phur and  mercury  together  in  a  mortar  (?)  8.  Heat  sugar  in 
a  dry  test-tube,  at  first  gently,  and  then  more  strongly.  Note 
color  and  odor.  9.  Mix  dry  soda  and  ta.rtaric  acid  in  a  mor- 
tar. Is  there  any  action  ?  What  occurs  when  you  add  water  ? 
Point  out  in  what  respect  the  changes  involved  in  experiments 
1-3  differ  essentially  from  those  in  4-9.  By  what  general' 
names  can  you  distinguish  the  two  different  kinds?  With 
which  does  chemistry  concern  itself?  Define  chemistry. 

Through  what  agencies  have  the  results  been  obtained  in 
experiments  4-9  ?  Has  any  gain  or  loss  of  matter  occurred 
in  any  of  them  ? 

(2)  The  products  resulting  from  5  and  6  cannot  be  further 
simplified,  i.  e.,  decomposed  into  dissimilar  substances.     They 
are  elements.*     What  are  water  and  red  oxide  of  mercury? 

i.  Dissolve  in  a  little  warm  nitric  acid,  the  black  substance 
obtained  by  heating  an  intimate  mixture  of  powdered  sulphur 
and  finely  divided  copper. 

Evaporate  the  solution  nearly  to  drynesy,  take 
up  in  water  and  filter.  What  remains  on  the  filter  ? 
Place  the  filtrate  in  a  beaker,  dip  the  platinum 
electrodes  of  a  battery  (one  or  two  Bunsen  cells) 
into  it  (Fig.  3),  and  allow  the  current  to  act  for 
10  minutes.  What  do  you  observe  upon  the 
platinum  foil,  forming  the  negative  pole  ?  What 
changes  have  the  copper  and  the  sulphur  undergone  in  this 
experiment  ? 

(Study  pp.  18-26,  in  Richter's  Chemistry.) 

(3)  Metals  and  Non-metals. — (See  Richter,  p.  20.) 

*  The  instructor  should  here  develop  the  idea  of  element  more  fully. 


FIG. 


HYDROGEN. 


CHAPTER    III. 


HYDROGEN.— H. 

(1)  Put  several  pieces  of  granulated  zinc  into  a  test-tube 
and  pour  dilute  hydrochloric  acid  upon  them.     What  occurs? 

(2)  Arrange   the  apparatus   shown 
in  Fig.  4.     The  flask  should  contain 
about   15   grams  of  zinc,  and  dilute 
sulphuric  acid  is  poured  through  the 
funnel  tube.     When  all  the  air  in  the 
apparatus  has  been  displaced  (ask  for 
precautions  ! )   collect   six  large    test- 
tubes  full  of  the  gas  over  water. 

(3)  What  are  its  properties ?    Will  it  burn?    Support  com- 
bustion ?     Is  it  lighter  than  air  ? 

Invert  a  test-tube  containing  one-third  of  its  volume  of 
water  in  a  dish  of  water,  and  displace  the  water  in  the  tube 
by  hydrogen.  What  happens  when  the  resulting  mixture  of 
air  and  hydrogen  is  brought  in  contact  with  a  flame  ? 

(4)  Connect  the  stout  copper  wires  of  a  Bunsen  battery 
(three   or   four   cells)  with  a  loop   of  thin    platinum  wire. 
Introduce   the   incandescent  wire   into   an    inverted  beaker 
containing  hydrogen.     What  takes  place  ? 

(5)  Over  a  small  flame  of  burning  hydrogen  place  a  rather 
wide  glass  tube.     Slowly  lower  the  tube  until  a  musical  sound 
is  heard.     Explain  this  phenomenon. 

(6)  i.   To  learn  what  becomes  of  hydrogen  when   it  burns 
in  air,  arrange  apparatus  as  in  Fig.  5.     The  gas  is  led  from 
the  evolution   flask  A,  into  a  bottle  containing  concentrated 
sulphuric  acid,  and  then   passes  through  a  tube  filled  with 
pieces  of  calcium  chloride.     The  gas  which  escapes  is  free 
from  moisture.     Burn  it  under  a  cold  glass  jar.     What  do  you 


14  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

obtain  ?  2.  Fill  a  small  flask  with  a  mixture  of  one  vol.  of 
hydrogen  and  five  vols.  of  air ;  cork ;  invert  the  flask  several 

times  to  mix  the  gases ;  wrap 
a  towel  around  it  and  bring 
its  mouth  to  a  flame.     Re- 
0  )    suit? 

(7)  Hydrogen  is  not  the 
only  Product  of  the  action  of 
Sulphuric  Acid  upon  Zinc. 

Pour  some  of  the  liquid 
remaining  in  the  flask,  in 

which  hydrogen  was  generated,  into  a  porcelain  dish.  Evap- 
orate to  about  one-third  of  the  original  bulk ;  allow  to  stand 
several  hours.  You  will  now  discover  that  the  solution  is 
full  of  colorless  crystals.  These  are  zinc  sulphate  or  white 
vitriol — a  salt,  ZnSO4  -|-~7H2O.  Write  the  equation  of  the 
reaction. 

(8)  Determine  the  Weight  of  Hydrogen  generated  by  a  given 
Weight  of  Zinc. 

A  piece  of  zinc  (not  more  than  .02  gram)  is  accurately 
weighed,  and  placed  under  a  funnel  in  a  beaker 
(Fig.  6).  The  latter  is  then  nearly  filled  with 
water,  so  that  the  entire  funnel  is  under  the 
surface.  A  test-tube  containing  dilute  sulphuric 
acid  is  lowered  over  the  stem  of  the  funnel. 
Hydrogen  appears  and  collects  in  the  tube. 
When  all  the  zinc  has  disappeared,*  transfer 
the  tube  containing  the  hydrogen  to  a  larger 
vessel,  holding  water.  Measure  the  volume  of 
the  gas  by  marking  the  tube  where  the  inner  and  outer  levels 
of  water  are  even,  and  then  weighing  or  measuring  the 


*  This  may  be  hastened  by  bringing  a  spiral  of  platinum  wire  in  contact 
with  the  zinc. 


\trNJVERSITY 

HYDROGEN.  15 

quantity  of  water  that  it  will  hold  to  that  mark.     Note  the 
temperature  of  the  water,  and  the  height  of  the  barometer. 

The  weight  of  the  hydrogen  is  found  by  multiplying  the 
volume  by  the  weight  of  one  cc.,  i.e.,  .0000896  gram.  Before 
this  can  be  done,  however,  it  is  necessary  to  reduce  the  volume 
of  the  gas  to  o°  C.  and  760  mm.,  as  the  above  value  has  been 
determined  under  these  conditions.  If  v  =  volume  observed, 
t  =  temperature,  and  p  =  pressure,  then 

=  VXP 

(I  +  at)  X  760 
and  W  =  v0  X  .0000896.  a  =  .003665.* 

To  calculate  the  quantity  of  zinc  necessary  to  generate  a 

unit  of  hydrogen,  we  say — 

FIG.  7. 
Wt  of  H  :  Wt  of  Zn  :  :   i   :   x. 

x  here  stands  for  the  equivalent  weight 
of  zinc. 

The  equivalent  weights  of  some  other 
metals,  such  as  iron,  cadmium  and  mag- 
nesium, can  be  determined  in  the  same 
manner.  Magnesium  gives  the  most  satisfactory  results. 

(9)  Decompose  water  by  electrolysis  and  test  the  products. 

(10)  Wrap  a  small  piece  of  sodium  in  paper  and  place  it, 
with  forceps,  under  the  mouth  of  a  test-tube  filled  with  water, 
and  inverted  in  water  (Fig.  7)  contained  in  a  dish.     Repeat 
this  until   the  test-tube   is  filled  with  the  gas.     Test  it   for 
hydrogen. 

What  becomes  of  the  metal  ?     Write  the  reaction, 
(n)  Construct  the  apparatus  shown  in  Fig.  8. 
Water  is  heated  to  boiling  in  the  flask  A,  and  the  steam 
led  over  iron  filings  or  wire,  heated  to  redness  in  an  iron  tube. 

*  Tension  of  aqueous  vapor  is  here  neglected. 


i6 


EXPERIMENTS    IN    GENERAL    CHEMISTRY. 


Collect  the  escaping  gas  over  water.     Test  it  for  hydrogen 
Note  its  odor  (?). 

Is  the  iron  changed  ?     Equation  ? 

(12)  Into  a  tube  of  hard  glass  (six  to  eight  inches  in  length) 


FIG.  8. 


place  a  weighed  quantity  (one  to  two  grams)  of  cupric  oxide 
contained  in  a  boat  j  connect  the  tube  with  a  calcium-chloride 
tube  of  known  weight  (Fig.  9).  Pass  a  current  of  hydrogen, 
dried  by  passing  through  concentrated  sulphuric  acid  or  cal- 


FIG.  9. 


cium  chloride,  over  the  oxide  of  copper.  When  the  air  is 
completely  expelled  (?)  apply  a  gentle  heat  to  the  part  of  the 
tube  containing  the  oxide.  Observe  the  glowing  of  the 
mass.  When  the  change  is  complete,  cool  and  determine 


FIRST    NATURAL   GROUP   OF    ELEMENTS — CHLORINE.          17 

the  loss  in  weight  of  the  boat,  and  the  gain  in  the  calcium 
chloride  tube.  Explain  the  reaction. 

Problems. — i.  How  much  hydrogen  can  be  obtained  from 
zinc  and  299  grams  of  sulphuric  acid?  2.  How  much  zinc 
and  sulphuric  acid  are  necessary  to  furnish  100  grams  of  hydro- 
gen ?  3.  Suppose  you  have  found  that  .015  gram  of  magnes- 
ium yields  15.2  cc.  of  hydrogen  at  20°  C.  and  750  mm.,  what 
is  the  equivalent  weight  of  that  metal  ?  4.  How  many  cc. 
of  hydrogen  can  be  obtained  from  two  grams  of  sodium  and 
water  ?  5 .  How  many  grams  of  water  can  be  decomposed  by 
5  grams  of  iron  ;  by  how  much  is  the  weight  of  the  latter 
increased?  6.  10  grams  of  cupric  oxide  will  yield  how  much 
copper  upon  heating  in  hydrogen  ? 

Give  a  brief  summary  of  what  you  have  learned  about  hydro- 
gen? 

(Study  Richter,  pp.  39-47-) 


CHAPTER    IV. 

FIRST  NATURAL  GROUP  OF  ELEMENTS— CHLORINE, 
BROMINE,  IODINE,  FLUORINE. 

CHLORINE.— Cl. 

(1)  Into  a  test-tube  put  manganese  dioxide  and  concen- 
trated hydrochloric  acid.     Note  what  happens  both  before 
and  after  heating. 

(2)  Use  apparatus  (shown  in  Fig.  10)  for  preparing  larger 
quantities  of  chlorine.     The  manganese  dioxide  should  be  in 
the  form  of  small  lumps  (not  powder).   Heat  the  mixture  gently, 
pass  the  chlorine  through  a  small  quantity  of  water  and  collect 
it  either  by  downward  displacement  or  over  warm  water. 

3 


UNT  VR-RRTT-V* 


i8 


EXPERIMENTS    IN    GENERAL   CHEMISTRY. 


FIG.  10. 


Write  the  reaction.     How  many  atoms  of  chlorine  are  lib- 
erated ?     How  many  molecules  ? 

(3)  i.  What  is  the  normal  condition  of 
this  element?     2.  Is  it  lighter  than  air? 
3.   Is  it  inflammable?     4.  Does  it  support 
combustion  ? 

To  obtain  answers  to  these  questions, 
fill  a  number  of  test-tubes  with  dry  chlo- 
rine, and  proceed  as  under  hydrogen. 

(4)  Collect  five  large  test-tubes  full  of 
the  dry  gas,  and  cover  them  with  watch 
glasses. 

Into  i  throw  a  little  pulverized  antimony. 
Into  2  carefully  introduce  a  piece  of  phosphorus. 
Into  3  insert  tissue  paper  moistened  with  oil  of  turpen- 
tine.* 

Into  4  introduce  colored  flowers. 
Into  5  pour  a  little  litmus  solution. 
What  are  the  results? 

(5)  Fill  a  test-tube  with  chlorine,  and  a  second  one  of  the 
same  size  with  hydrogen.     Bring  the  tubes  together,  mouth 
to  mouth,  and  mix  the  gases  by  repeated  inverting.     Apply  a 
flame  to  the  open  mouth  of  each  tube  (?). 

(6)  Invert  a  bottle  filled  with  chlorine  over  water  saturated 
with  the  same  gas.     What  follows  in  the  course  of  a  few  hours' 
exposure  to  sunlight?     Can  you  account  for  results  in  experi- 
ments (4),  (5),  and  (6)?     Why  should  the  gas  be  collected 
over  warm  water  ? 

(7)  Determine  the  Weight  of  a  Litre  of  Chlorine. — Arrange 
apparatus  as  shown  in  Fig.  n. 

In  the  evolution- flask  place  a  mixture  of  equal  weights  of 


*  It  is  well,  when  the  turpentine  is  old,  to  gently  warm  it,  and  then 
saturate  the  tissue  paper. 


FIRST   NATURAL   GROUP   OF   ELEMENTS — CHLORINE.          19 

salt  and  manganese  dioxide.     Add  sulphuric  acid,  previously 
diluted  with  its   own  volume  of  water 
(pour  the  acid  into  the  water  !  ).     Heat 
gently.     Chlorine  is  evolved,  and  dried 
by   passing   through    concentrated   sul- 
phuric acid,  after  which  it  is  led  into 
the  perfectly  dry  flask  £.*'   When  this  is 
filled,  which  you  ascertain  by  the  color 
of  the  gas  in  the  neck,  slowly  withdraw 
the  tube  and   cork   the   flask   at   once. 
Weigh  .  the  flask.     Read   the   barometer   and    thermometer. 
Determine,  also,  the  weights  of  the  flask  filled  with  air  and 
with  water. 

Calculation. — 

Capacity  of  flask, c 

Temperature, t 

Pressure, p 

Flask  filled  with  air, w 

"             "          chlorine, w' 

Wt.  of  a  litre  of  air, l-293  grm- 

"               "         chlorine, x 

The  weight  of  the  air  filling  the  flask  is    c  x  p  X  -OOI293 

(i  +  .00367  t)  760. 

The  difference  between  this  and  w  is  the  weight  of  the 
vacuous  flask.  Subtract  this  from  w'.  The  remainder  is  the 
weight  of  the  chlorine  (W).  Reduce  the  vol.  of  the  chlorine 
to  o°  C.  and  760  mm.  (see  under  hydrogen) ;  it  is  v0  — 

axp  ,,          •i^.rT.L  Wx  1000 

1. ,  and  the  weight  of  i  litre,  x  = , — -. 

(i  +  .00367  t)  760  v° 

How  much  heavier  is  one  litre  of  chlorine  than  a  litre  of 
hydrogen  ?  . 

*  To  prevent  the  diffusion  of  the  gas  into  the  air  a  plug  of  cotton  should 
be  placed  in  the  neck  of  c. 


20  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

Write  the  reaction  involved  in  the  above  method  for  pre- 
paring chlorine. 

Problems, — i.  How  many  litres  of  chlorine  can  be  obtained 
from  one  kilo  of  manganese  dioxide  and  hydrochloric  acid  ? 
2.  What  weight  of  salt  is  required  to  prepare  100  litres  of 
chlorine?  3.  How  many  pounds  of  sodium  sulphate  and 
manganese  sulphate  will  be  formed  in  the  preparation  of  100 
litres  of  chlorine  gas  ?  4.  Calculate  the  number  of  grams  of 
chlorine  that  two  litres  of  water  will  absorb,  provided  the  latter 
takes  up  twice  its  volume  of  the  gas?  Write  out  your  deduc- 
tions from  the  above  experiments  on  chlorine. 

(Read  Richter,  pp.  49-52.) 

HYDROGEN  CHLORIDE.— HC1. 

(1)  Repeat  the  explosion  of  equal  volumes  of  chlorine  and 
hydrogen.     Quickly  cover  the  mouth  of  the  flask,  and   im- 
merse it  under  water.     Does  the  latter  rise  ?     Put  a  drop  of 
the  liquid  on  the  tongue  and  note  the  taste.     Add  some  blue 
litmus  solution.     Is  there  any  change  ? 

(2)  The  product  of  the  union  of  hydrogen  and  chlorine  is 
a  colorless  gas.     It  is  called  hydrogen  chloride.     It  is  usually 
prepared  by  the  action  of  sulphuric  acid  upon  salt,  thus  :  — 

2NaCl  +  H2S04  =  2HC1  +  Na2SO4. 
or,  better,         NaCl  +  H2SO4  =  HC1    -f  NaHSO4. 

The  apparatus  employed  here  is  the  same  as  that  used  in 
making  chlorine  (Fig.  10). 

(3)  Determine  the  Properties  of  Hydrogen  Chloride  as  under 
Hydrogen  and  Chlorine. 

What  new  property  appears  here?  Fill  a  long  dry  glass 
tube  with  the  gas,  and  quickly  bring  it  into  a  basin  contain- 
ing water  colored  blue  with  litmus.  What  happens?  What 
does  hydrogen  chloride  gas  yield  on  dissolving  in  water? 

(4)  In  the  preparation  of  hydrogen  by  the  action  of  sodium 


HYDROGEN 


21 


Cl 


upon  water,  it  was  observed  that  the  liquid  became  soapy  to 
the  touch,  and  acquired  the  property  of  turning  red  litmus 
blue.  Prepare  such  a  solution.  To  it  add  a  few  drops  of 
litmus,  and  then  a  solution  of  hydrogen  chloride  (gradually) 
from  a  burette,  until  the  blue  color  just  begins  to  turn. 
Evaporate  the  resulting  liquid  to  crystallization.  Dissolve 
and  recrystallize  the  product.  It  appears 
in  cubes,  and  has  the  taste  of  common  salt. 
It  does  not  affect  either  red  or  blue  litmus. 
We  say  it  is  neutral  in  reaction.  The  sub- 
stance is  chloride  of  sodium  or  common  salt. 
What  is  a  salt  ?  An  acid  ?  A  base  ?  How 
can  you  obtain  hydrogen  chloride  and  chlo- 
rine from  sodium  chloride? 

(5)  Burn  Hydrogen  in  an  Atmosphere  of 
Chlorine,  and  Chlorine  in  Hydrogen. 

Generate  chlorine  as  already  described  (p.  17)  and  collect 
it  in  a  large  cylinder.     Into  this  introduce  a  burning  jet  of 

hydrogen  (Fig.  12).     Does  it  continue  burning? 

What  is  the  appearance  of  the  flame  ?     To  show 

the  combustion  of  chlorine  in  hydrogen  arrange 

apparatus  as  in  Fig.  13. 

(6)  To  determine  the  weight  of  a  litre  of  hydro- 
chloric  acid  gas,  proceed  exactly  as  under  chlorine. 

(7)  Determine  the  Composition  of  Hydrochloric 
Acid  Gas  by  Volume. 

i.  Fill  a  perfectly  dry  and  graduated  tube  with 
hydrogen  chloride.  Close  the  open  end  with  the 
thumb,  and  opening  the  tube  for  a  moment, 
quickly  pour  in  about  10  cc.  of  sodium  amalgam 
(see  sodium,  p.  53).  Close  the  tube  at  once  with 
the  thumb,  slightly  moist,  and  shake  well.  Invert 

the  tube  in  a  large  beaker  of  water,  and  remove  the  thumb. 

The  amalgam  will  drop  into  the  water,  and  the  latter  will 


™' 


H 


22  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

rush  up  into  the  tube,  filling  it  nearly  half  full.  Immerse  the 
tube  so  that  the  water  in  it  and  that  in  the  beaker  are  on  the 
same  level.  This  is  done  to  measure  the  hydrogen  under 
atmospheric  pressure.  Read  the  volume  of  the  residual  gas 
and  measure  also  the  volume  of  the  mercury. 

Calculation.  — 

Capacity  of  tube, a 

Vol.  of  mercury,  . b 

Vol.  of  hydrogen, c 

a  — b 
c  =  

2 

(8)  Add  hydrochloric  acid  to  solutions  of  silver  nitrate ; 
of  mercurous  nitrate ;  and  of  lead  acetate.  What  do  you 
observe  in  each  case?  Boil  the  precipitate  formed  in  the 
lead  solution  with  water.  Cool,  and  note  result. 

BROMINE.— Br. 

(1)  Allow  a  drop  of  bromine  to  fall  upon  a  heated  watch 
glass;  cover  it  quickly  with  a  beaker.     What   is  the  color  of 
the  vapor?     Dissolve  one  drop  of  bromine  in  each  of  the 
following   solvents   contained   in  test-tubes;    water,  alcohol, 
ether,  carbon  disulphide,  and  chloroform.     Note  the  relative 
solubilities,  and  the  color  of  each  solution. 

(2)  i.  Pass  chlorine  through  an  aqueous  solution  of  potas- 
sium   bromide.      What    happens?     2.   To  a  portion   of  the 
product  add  a  few  drops  of  carbon  disulphide,  and  agitate  the 
mixture;  what  is  the  result?     3.  To  another  portion  of  the 
solution,  containing  free  bromine,  add  a  few  drops  of  a  starch 
emulsion.*     Result? 

*  The  starch  emulsion  for  this  purpose  can  be  prepared  as  follows  :  One 
gram  of  starch  is  well  ground  in  a  mortar,  with  very  little  water,  to  creamy 
consistence.  It  is  then  poured  into  200  cc.  of  boiling  water.  Allow  to 
subside,  decant  the  clear  supernatant  liquid  and  use  it  for  the  test. 


FIG.  14. 


FIRST    NATURAL    GROUP    OF    ELEMENTS— IODINE.  23 

(3)  Devise  a  method  for  preparing  bromine  from  potassium 
bromide. 

(4)  Prepare  Hydrobromic  Add. — In  a  small  flask  cover  five 
grams  of  red  phosphorus  with   10  cc.  of  water,  and  from  a 
funnel,    provided    with 

a  stop-cock,  gradually 
allow  50  grams  of  bro- 
mine to  run  in.* 

The  gas  is  purified  by 
conducting  it  through 
a  U-tube,  containing 
moistened  pieces  of 
phosphorus  and  glass 
(Fig.  14),  and  led  into 
water  to  obtain  the 
aqueous  solution.  How  would  you  collect  the  gas? 

(5)  Add  hydrobromic  acid  to  solutions  of  silver  nitrate, 
mercurous  nitrate  and  lead  nitrate — do  the  resulting  bromide 
precipitates  differ  much  from  the  corresponding  chlorides? 

IODINE.— I. 

(1)  i.   Place  an  iodine  crystal  upon  a  warm  plate,  and  note 
color  of  vapor.     2.   Test  the  solubility  of  iodine  in  the  same 
solvents  as  were  used  with  bromine ;  what  are  the  colors  of  the 
resulting  solutions  ? 

(2)  i.  Pass  chlorine  into  a  solution  of  potassium  iodide. 
Divide  the  resulting  liquid  into  three  parts.     To  one  of  these 
add  about  5  c  c.   of  ether  and  agitate  (?).     Shake  a  second 
portion  with  carbon  disulphide  or  chloroform.     To  the  re- 
maining portion  add  some  starch  emulsion  (?).     2.   Repeat 


*  As  it  is  rather  difficult  to  weigh  bromine  upon  a  balance,  calculate  the 
volume  corresponding  to  the  weight  given  and  measure  out  the  same  in  a 
cylinder. 


rcrNi 

r- 


OF  THE 

UNIVERSITY 

OF 


24  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

this  experiment,  substituting  bromine  water  for  the  chlorine. 
Avoid  excess  of  chlorine  as  well  as  bromine  (?). 

What  conclusion  do  you  draw  from  these  experiments  re- 
lative to  the  affinity  of  the  halogens  for  potassium  ? 

(3)  Pass  hydrogen  sulphide  gas  (H2S)  into  50  cc.  of  water, 
and  add  powdered  iodine  till  the  brown  color  no  longer  dis- 
appears.    Warm,  filter  (?)  and  distil  the  filtrate.     The  product 
is  what  ? 

How  is  gaseous  hydriodic  acid  prepared  ? 

(4)  Precipitate  solutions  of  silver  nitrate  (AgNO3),  mer- 
curous  nitrate  (HgNO3),  lead  nitrate  (Pb(NO3)2),  and  mercuric 
chloride  (HgCl2),  with  potassium  iodide.     Note  result  in  each 
case.     Redissolve  the  lead  iodide  in   water.     What  do  you 
observe  on  cooling  the  solution  ? 

FLUORINE.— Fl. 
In  what  manner  has  this  element  been  isolated  ? 

(1)  In  a  lead  dish  (or  platinum  crucible)  place  one  gram  of 
pulverized  fluor  spar  (CaFl2).     Add  concentrated    sulphuric 
acid ;  cover  the  dish  or  crucible  with  a  watch-glass  coated  with 
paraffin,  through  which  characters  have  been  drawn  with  a  fine 
point.     Heat  gently  for  a  few  minutes. 

What  do  you  observe  on  removing  the  paraffin  ? 

(2)  Can  you  liberate  fluorine  from  a  fluoride  ? 
Problems. — i.   How  much  sodium  bromide,  sulphuric  acid 

and  manganese  dioxide,  are  necessary  to  produce  one  cu. 
metre  of  bromine  vapor  at  20°  C.  and  745  mm.  ?  2.  What  per 
cent,  of  hydrogen  iodide  does  a  liquid  contain,  which  repre- 
sents a  solution  of  50  litres  of  the  gas  in  one  litre  of  water? 
3.  TO  grams  of  fluor  spar  will  give  what  weight  of  hydrogen 
fluoride?  4.  How  much  salt  and  sulphuric  acid  will  be  re- 
quired to  prepare  six  litres  of  muriatic  acid  of  sp.  gr.  1.17? 
What  volume  would  the  hydrogen  chloride  in  these  six  litres 
occupy  at  735  mm.  pressure  and  22°  C.?  5.  What  is  the  per- 


SECOND    NATURAL   GROUP   OF    ELEMENTS — OXYGEN.         25 

centage  of  hydrochloric  acid  in  a  solution  of  which  1 7  cc. 
dissolve  exactly  two  grams  of  metallic  magnesium?  What  is 
the  volume  of  hydrogen  liberated  at  760  mm.  and  o°  ? 


CHAPTER  V. 

SECOND  NATURAL  GROUP  OF  ELEMENTS— OXYGEN, 
SULPHUR,  SELENIUM,  TELLURIUM. 

OXYGEN.— O. 

(1)  Preparation.  —  i.  Weigh  the  hard  glass  tube  a  (Fig. 
15),  and  introduce  a  weighed  quantity  (about  .5  gram)  of  red 
oxide  of  mercury.     Ignite  strongly  ;  collect  the  liberated  gas, 
and  measure  it.    Weigh  the  tube  with  the  residue.     What  are 
the  products  of  the  ignition? 

(2)  Prepare  more  of  the  gas,  as  follows :     Mix  equal  parts 
of  potassium  chlorate  and  pulverized  manganese  dioxide ;  heat 
in  a  tube  of  hard  glass  or  small  retort.     Collect  the  gas  in 
bottles  over  water  (Fig.  15). 

Into  No.  i  lower  a  piece  of  ignited  sulphur  on  an  iron 
spoon.  Note  result.  Add  water  after  the  combustion!?). 

Into  No.  2  introduce  a  small  piece  of  burning  phosphorus 
(care  !).  Proceed  as  in  No.  i. 

Into  No.  3  introduce  ignited  charcoal.  Treat  as  before. 
Add  now  a  few  drops  of  blue  litmus  to  the  contents  of  each 
bottle.  Any  change  ? 

Into  bottle  No.  4  introduce  a  fine  watch  spring,  previously 
heated  at  one  end  and  dipped  into  powdered  sulphur.  Result  ? 

Is  oxygen  heavier  or  lighter  than  air?  Has  it  color,  taste, 
or  odor  ?  Will  it  burn  ?  Does  it  support  combustion  ? 

What  other  methods  can  be  used  for  preparing  oxygen  ? 
4 


26 


EXPERIMENTS   IN   GENERAL   CHEMISTRY. 


(3)  Determine  the  Weight  of  a  Litre  of  Oxygen. 

Arrange  apparatus  shown  in  Fig.  16  ;  a  is  a  tube  of  hard 
glass,  whose  weight  is  known  ;  it  contains  a  weighed  amount 
of  potassium  chlorate  (about  0.3  gram).  The  bottle  A  is  filled 
with  water,  b  is  a  clip  and  da.  beaker.  The  exit  tube  should 
be  filled  with  water  at  the  beginning  of  the  experiment. 
Open  the  clip,  heat  a  to  bright  redness,  and  receive  the  water 
displaced  by  the  oxygen  in  d.  When  no  more  gas  is  evolved, 


FIG.  15. 


FIG.  16. 


cool;  allowing  the  rubber  tube  to  dip  under  the  water  in  the 
beaker.  Some  of  the  water  will  be  drawn  back  into  the  bot- 
tle (?).  Measure  the  volume  of  the  water  in  d.  Note  the 
temperature  of  the  air,  and  the  height  of  the  barometer. 
Weigh  a,  containing  residue  of  potassium  chloride  (KC1). 
Calculation. — 

Weight  of  the  tube, a 

Weight  of  potassium  chlorate  and  tube, b 

Weight  of  potassium  chlorate, b  —  a 

Volume  of  water  collected, v 

Barometric  pressure, p 

Temperature, t 

Aqueous  tension  at  t, p' 

Weight  of  potassium  chloride  and  tube, c 

v  X  (p  —  p')  (b  —  c)  X  looo 

(I +  .003671)  X  76o  ~Vo~~ 


Vo= 


j*  A  v  JL.jtts4.-j;  *  / 


SECOND    NATURAL   GROUP   OF   ELEMENTS  —  WATER. 


27 


Dissolve  the  residual  potassium  chloride  in  water,  and  to 
its  solution  add  nitrate  of  silver  (?).  How  does  potassium 
chlorate  behave  under  like  conditions  ? 

(4)  Give  a  summary  of  your  work  upon  oxygen. 

Problems.  —  i.  How  much  oxygen,  by  weight  and  volume, 
can  be  obtained  from  54  grams  of  mercuric  oxide?  2.  Heat 
will  expel  what  volume  of  'Oxygen  from  2.45  grams  of  potas- 
sium chlorate  ?  3.  How  much  mercuric  oxide  is  necessary  to 
yield  one  cu.  d.  m.  of  oxygen  ?  4.  How  many  times  is 
oxygen  heavier  than  hydrogen  ? 

OZONE.—  03. 

(i)  Pour  water  on  clean  pieces  of  phosphorus  to  half  cover 
them  ;  invert  a  large,  clean  jar  over  this  and  allow  to  stand 
for  several  hours.  Test  the  air  under  the  jar  for  ozone.  For 
this  purpose  use  paper  impregnated  with  a  mixture  of  starch 
paste  and  potassium  iodide.  What  occurs  ? 

(Read  Richter,  pp.  85-89.) 

COMPOUNDS  OF  OXYGEN  AND  HYDROGEN. 
WATER.—  H2O. 

(i)  Arrange  the  distillation  apparatus  (Fig.  17)  and  prepare 
about  100  cc.  of  distilled  water.  Note  its  taste  and  odor. 
Test  it  for  chlorides  with  silver  nitrate.  Does  it  leave  a  resi- 
due upon  evaporation? 
What  action  has  it  on 
litmus? 

What  is  meant  by 
the  hardness  of  water? 
What  is  the  under- 
standing of  temporary 
and  permanent  hard- 
ness? 

Determination  of  Hardness.  —  Dissolve  one  gram  of  pure  cal- 


FlG- 


28  EXPERIMENTS   IN   GENERAL   CHEMISTRY. 

cium  carbonate  in  50  cc.  of  dilute  hydrochloric  acid.  Evap- 
orate this  solution  to  dryness  on  a  water-bath,  and  take  up 
the  residue  in  50  cc.  of  distilled  water.  Each  cc.  of  this  so- 
lution will  correspond  to  o.ooi  gram  of  calcium  carbonate. 
Next  dissolve  about  13  grams  of  castile  soap  in  a  mixture  of 
500  cc.  alcohol  and  500  cc.  of  water.  Filter  if  necessary. 
Determine  the  strength  of  this  solution  so  that  one  cc.  of  it  will 
equal  one  cc.  of  the  first  solution  or  o.ooi  gram  CaCOs.  To 
this  end  remove  12  cc.  of  the  first  solution  to  a  flask  and  di- 
lute with  water  to  70  cc.  Fill  a  burette  with  the  soap  solution 
and  allow  the  latter  to  run  into  the  lime  water,  one  cc.  at  a  time, 
shaking  after  every  addition,  until  a  lather  is  formed  which 
lasts  for  about  five  minutes.  Note  the  volume  consumed. 
Dilute  so  that  12  cc.  of  the  water  require  13  cc.  of  the  soap 
solution.  One  cc.  soap  is  allowed  for  the  distilled  water.  We 
can  now  consider  the  soap  solution  standardized ;  one  cc.  of  it 
is  equivalent  to  o.ooi  gram  of  calcium  carbonate  (CaCO3). 

In  determining  the  hardness  in  a  natural  water  use  70  cc. 
and  introduce  the  soap  solution  until  a  permanent  lather  is 
produced ;  deduct  one  cc.  of  the  volume  consumed,  and  the  dif- 
ference will  represent  the  hardness  of  the  water  in  terms  of 
calcium  carbonate.  This  result  gives  the  total  hardness. 
How  would  you  ascertain  the  permanent  and  temporary  hard- 
ness? What  action  has  the  soap  upon  the  lime  water? 

Apply  all  these  tests  to  a  natural  water  (except  rain). 

(2)  i.  Heat  a  little  vegetable  matter  in   a  dry  test-tube. 
2.  Heat  fresh  meat  in  the  same  manner.     3.  Carefully  heat 
crystals  of  zinc   or   copper  sulphate  in  a   test-tube.     What 
happens  in  these  experiments?     4.  Expose  clear  crystals  of 
sodium  phosphate,  on  a  watch  crystal,  to  the  air.     5.  Do  the 
same  with  pieces  of  calcium  chloride.     Results  ? 

(3)  Determine  the  Quantitative  Composition   of  Water. 

i.  The  composition  of  water  by  weight  follows  from  the  ex- 
periment of  reducing  oxide  of  copper  described  under  hydro- 
gen. 


SECOND    NATURAL   GROUP   OF   ELEMENTS — WATER. 


29 


2.  The  relative  volumes  with  which  oxygen  and  hydrogen 
unite  to  form  water,  are  determined  either  by  analysis  or  syn- 
thesis.   The  former  has  been  performed  in  electrolyzing  water. 

3.  Fill  a  eudiometer   (Fig.   18)   with  water.     Through   a 
rubber  tube  admit  about  50  cc.  of  oxygen  and  then  a  like 
volume  of  hydrogen.     (If  the  eudiometer  is  not  graduated, 
mark  these  with  rubber  bands.)      Close  the  open  end  with 
your  thumb,  leaving  some  air  to  serve  as  a  cushion  beneath  it, 
and  pass  the  spark.     Remove  the  thumb,  and  pour  in  enough 
water  to  make  the  levels  equal  in  both  limbs.     What  is  the 


FIG.  18. 


FIG.  19. 


amount  of  the  contraction  ?     What  is  the  residual  gas  ?     Test 
it. 

(4)  Determine  the  Weight  of  a  Litre  of  Steam. — Use  the 
apparatus  of  Victor  Meyer  shown  in  Fig.  19.  Cisa  vessel 
containing  aniline.  A  small  glass  tube  is  weighed  and  filled 
with  water  (not  more  than  .02  gram).  Heat  the  aniline  to 
its  boiling  point,  and  continue  heating  until  the  temperature 
is  constant  (?).  Now  drop  the  tube  containing  the  water 
through  the  side-tube  b  of  the  vessel  d  (the  bottom  of  which 
should  be  protected  with  a  layer  of  asbestos)  and  quickly 
re-cork.  When  the  fall  of  water  in  the  graduated  tube  ceases, 


30  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

read  the  volume  of  gas,  and  note  the  temperature  and  pres- 
sure of  the  air. 

The  calculation  is  analogous  to  that  used  under  oxygen  ? 

(5)  Perform  experiment  2,  p.  100  in  Richter. 

How  many  "volumes  of  steam  result  from  the  combination 
of  two  volumes  of  hydrogen  and  one  volume  of  oxygen  ? 

How  would  you  deduce  the  molecular  formula  of  water 
from  the  preceding  experiments  ? 

HYDROGEN  PEROXIDE.— H2O2. 

(1)  Add  moist  hydrated  barium  peroxide  to  cold  dilute 
sulphuric  acid.     Filter.     What  does  the  filtrate  contain  ? 

(2)  i.  Add   a  solution   of  potassium   iodide,   containing 
starch,   to  a  portion   of  this  liquid  (?).     Ferrous   sulphate 
hastens  the  reaction.     2.   Cautiously  add  a  dilute  solution  of 
potassium  permanganate  to  another   portion  (?).     3.  To  a 
third  portion,  add  a  few  cc.  of  ether  and  a  drop  of  potassium 
dichromate.     Shake  the  mixture  and  observe  the  result. 

COMPOUNDS  OF  OXYGEN  AND  CHLORINE. 

(i)  Make  a  dilute  solution  of  caustic  potash,  and  conduct 

chlorine  into  it  until  the  latter  is  no  longer  absorbed.     Treat 

one  portion   of  the   product   with   hydrochloric   acid,    and 

another  with  sulphuric  acid.     What  re- 

FlG.  20. 

suits  ? 

(2)  Mix  10  grams  of  quicklime  with 
25  cc.  of  water.  After  the  slaking  is 
finished,  conduct  chlorine  into  the  mix- 
ture until  it  is  no  longer  absorbed. 

Add  hydrochloric  acid  to  one  portion 
and  sulphuric  acid  to  a  second  portion. 
What  is  set  free  ?     Does  it  bleach  ? 

(3)  Pass  chlorine  into  a  hot  concentrated  solution  of  po- 
tassium hydroxide  till  it  ceases  to  be  absorbed  (Fig.  20). 


SECOND   NATURAL   GROUP   OF   ELEMENTS — SULPHUR.        3! 

What  separates  upon  cooling?  Recrystallize  the  product 
from  water.  Will  it  give  off  oxygen  upon  heating?  Try 
the  action  of  hydrochloric  acid  upon  a  crystal.  Allow  a 
drop  of  concentrated  sulphuric  acid  to  fall  upon  a  small 
crystal  and  warm  gently  (?).  Care  ! 

Observe  carefully  the  behavior  of  potassium  chlorate  upon 
heating  (?). 

SULPHUR.— S. 

(1)  Place  a  few  grams  of  powdered  sulphur  in  a  dry  test- 
tube,  and  heat  gradually.     Observe  and  describe  the  changes 
which  occur. 

(2)  Dissolve   a   little   sulphur    in   carbon   disulphide   and 
allow   to   stand   till   the   liquid   has   evaporated.     What  re- 
mains ? 

(3)  Determine   the   specific   gravity   of   sulphur.     Water, 
previously  boiled,  is  introduced  into  a  flask  provided  with  a 
mark  (Fig.   21).     It  is  essential  that  the  neck  of  the  flask 
should  be  narrow.     Weigh  the  flask,  then  place  an  additional 
lo-gram  weight  upon  the  right  hand  pan  of  the  balance 

and  small  pieces  of  sulphur  upon  the  left-hand  pan, 
until  the  pointer  is  again  in  the  middle.     Now  intro- 
duce  the   sulphur   into   the  flask.     Carefully  remove 
water  above  the  mark  and  re-weigh  the  flask  with  its 
contents.     The  loss  in  weight  will  represent  the  weight 
of  a  volume  of  water  equal  to  that  of  10  grams  of  sulphur. 
The  latter  divided  by  the  former  is  the  specific  gravity  of  the 
sulphur. 

(4)  Prepare  the  monoclinic  modification  of  sulphur  by  melt- 
ing about   10  grams  of  the   ordinary  variety  in  a  covered 
Hessian  crucible.     Cool;  and  as  soon  as  a  solid  crust  has 
formed  upon  the  surface,  pierce  it  and  allow  the  still  liquid 
portion  of  the  contents  to  run  out.     Note  the  shape  of  the 
crystals  upon  the  sides  of  the  crucible. 

(5)  To  obtain  fas. plastic  variety,  heat  20  grams  of  sulphur 


32  EXPERIMENTS   IN   GENERAL   CHEMISTRY. 

in  a  small,  round-bottomed  flask  until  it  boils,  and  pour  it  in 
a  thin  stream  into  cold  water. 

Test  the  solubility  of  the  product  in  carbon  disulphide. 
Preserve  a  portion  of  it  for  several  days.  Does  it  change  ? 

(6)  To  a  strong  solution  of  yellow  potassium  sulphide,  add 
hydrochloric  acid.     What  are  the  properties  of  the  separated 
sulphur  ? 

Give  a  brief  outline  of  the  element  sulphur ;  compare  it 
with  the  previously  studied  elements. 

SULPHUR   AND   HYDROGEN. 

(7)  Hydrogen  sulphide — (H2S) — is  formed   with  difficulty 
from  its  elements,  but  is  readily  obtained  by  the  action  of 
acids  upon  sulphides,  thus:— 

FeS  -f  H2SO4  =  FeSO4  -f  H2S  or  Sb2S3  +  6HC1  =  2SbCl3  +  sH2S. 

The  apparatus  to  be  used  is  the  same  as  that  employed  in 
preparing  hydrogen.  The  acid  used  should  be  dilute. 

(8)  What  are  the  properties  of  hydrogen  sulphide  ?     Is  it 
soluble  in  water?     Does  it  burn?     What  are  the  products  of 
its  combustion  ?     Hold  a  porcelain  plate  in  the  flame;  what 
results  ? 

(9)  Expose  a  portion  of  the  aqueous  solution  of  hydrogen 
sulphide  to  the  air.     What  causes  it  to  become  turbid  and  to 
lose  its  odor  ?     Pass  a  current  of  the  gas  into  strongly  acid 
solutions  of  potassium  chromate,  potassium  permanganate,  and 
ferric  chloride.     Describe  and  explain  the  occurring  changes. 

(10)  What. action  has  hydrogen  sulphide  water  on  litmus? 

(n)  Pass  hydrogen  sulphide  through  solutions  of  the  fol- 
lowing salts,  viz.: — copper  sulphate,  antimony  chloride,  lead 
nitrate,  arsenious  trioxide,  and  zinc  acetate.  Note  results 
carefully. 

Can  sulphides  be  prepared  in  another  manner?  (See 
Chap.  II,  §  i.) 


SECOND    NATURAL   GROUP   OF    ELEMENTS SULPHUR.        33 

(12)  Determine  the  Composition  of  Hydrogen  Sulphide. 
Into  a  bent  tube  of  hard  glass,  filled  with  mercury  (Fig. 

22),  introduce  dry  hydrogen  sulphide.*     Place  a  piece  of  tin 

in  the  bent  portion  and  heat  it.     Is  the 

volume  of  the  gas  changed  after  the  experi-  FlG-  22- 

ment,  and  what   becomes  of  the  piece  of 

tin  ?     Test  the  gas  remaining  in  the  tube. 

Do  your  results  enable  you  to  deduce  the 

molecular  formula  of  hydrogen  sulphide. 

(See  Richter,  4th  ed.,  p.  no.)     Trace  the 

similarity  between  hydrogen  sulphide  and  water.     Write  a 

summary  of  your  experiments  on  hydrogen  sulphide. 

SULPHUR   AND    CHLORINE. 

(13)  Sulphur  Mono  chloride. — i.  Prepare  this  compound  by 

conducting  dry  chlorine  over  molten  sulphur. 
The  product  which  distils  over  is  collected  in  a 
dry  test-tube,  kept  cold  by  immersion  in  ice 
water.  2.  Redistil  the  product.  Determine 
its  boiling  point  in  an  apparatus  similar  to  that 
pictured  in  Fig.  23.  Note  the  color  and  odor 
of  the  product.  Expose  some  of  it  to  the  air 
on  a  watch-glass,.  Add  water  to  another  por- 
tion contained  in  a  test-tube.  Note  carefully 
what  happens.  Write  the  reaction,  and  exam- 
ine for  all  the  products. 

SULPHUR    AND    OXYGEN. 

(14)  Burn  sulphur  in  the  air.     Result?    Burn  pyrite  (FeS2) 
in  the  air.     What  are  the  properties  of  the  resulting  com- 
pound ?     It  is  sulphur  dioxide — SO2. 

(15)  Fit  a  small  flask,   as  indicated   in   Fig.    24.     Place 

*  The  instructor  should  assist  in  performing  this  experiment, 

5 


34  EXPERIMENTS   IN   GENERAL  CHEMISTRY. 

copper  turnings  in  it,  then  add  sulphuric  acid  (strong) 
through  the  funnel  tube.  Warm.  Is  the  pro- 
duct the  same  as  that  obtained  in  14?  Is  it 
soluble  in  water?  Has  the  aqueous  solution  the 
same  properties  as  the  gas?  2.  Pass  some  of 
the  gas  into  solutions  of  potassium  dichromate 
and  potassium  permanganate  acidulated  with 
sulphuric  acid.  Repeat  these  experiments  with  . 
the  aqueous  solution  instead  of  the  gas.  What 
happens  in  each  case?  3.  Test  the  aqueous 
solution  of  sulphur  dioxide  with  litmus.  What 
is  this  solution  commonly  called  ?  4.  Fill  a  dry  jar  with  sul- 
phur dioxide  gas ;  introduce  colored  flowers.  Note  the  result. 

(16)  What  is  the  formula  of  sulphurous  acid  ?     How  many 
series  of  salts  can  it  form  ?     How  would  you  designate  the 
different  sodium  salts?     Add  hydrochloric  acid  to  a  solution 
of  sodium  sulphite.     What  follows  ?     Evaporate  the  solution 
to  dryness  and  examine  the  residue.     What  is  it  ?     Write 
the  reaction. 

SULPHUR  TRIOXIDE — SO3.     (Read  Richter,  p.  191.) 

(17)  Sulphuric  Acid — H2SO4. — To  prepare  sulphuric  acid 
arrange  apparatus  as  in  Fig.  25.    The  large  flask,  A,  represents 
the  lead  chamber  of  the  commercial  method.     The  cork  in 
it  is  provided  with  several  perforations  through  which  glass 
tubes  pass ;  these  serve  to  introduce  the  various  gases.     In 
flask  a  place   copper  turnings   and    concentrated   sulphuric 
acid.     When  this  mixture  is  heated  what  gas  is  evolved  ? 
Flask  b   contains  dilute  nitric    acid   and    copper   turnings. 
What  is  evolved  when  heat  is  applied?    Boil  water  in  flask  c. 
Let  air  enter   through  d.      e  serves  for  the  escape  of  the 
excess  of  gases  (?).     First  introduce  into  A  the  products  (?) 
from  a  and  b,  together  with  air — observe  the  frost-like  de- 
position upon  the  vessel — what  is  it  ?     Blow  steam  into  A  ; 
what  becomes  of  the  crystalline  sublimate?     When  10  cc.  to 


UNIVERSITY 


/ 


SECOND    NATURAL   GROUP   OF   ELEMENTS  —  SULPHUR.        35 

20  cc.  liquid  have  collected  in  A,  interrupt  the  experiment, 
and  study  the  product  carefully,  i.  Dilute  a  portion  of  it 
with  water  ;  what  happens  ?  2.  Test  a  portion  of  this  diluted 
solution  with  litmus  (?).  3.  Another  portion  neutralize  with 
sodium  hydroxide  and  evaporate.  What  is  the  residue  ? 
Does  it  contain  any  sulphur  ?  Prove  this.  4.  Add  barium 
chloride  to  a  third  portion  of  the  solution.  What  is  the 

FIG.  25. 


precipitate  ?  Is  it  soluble  in  water  or  in  hydrochloric  acid  ? 
5.  What  is  the  action  of  strong  sulphuric  acid  upon  wood  or 
paper  ?  Explain  the  cause  of  this  action. 

(18)  How  many  series  of  salts  can  sulphuric  acid  form. 
Prepare  ammonium  sulphate,  sodium  sulphate,  sodium  hydro- 
gen sulphate  and  copper  sulphate.  (Read  Richter,  pp. 
189-200.) 


EXPERIMENTS    IN    GENERAL    CHEMISTRY. 


FIG.  26. 


FIG.  27. 


CHAPTER    VI. 

NITROGEN    GROUP— NITROGEN,    PHOSPHORUS, 
ARSENIC,  ANTIMONY  AND  BISMUTH. 

NITROGEN.— N. 

(1)  Preparation. — i.  In  a  dish  swimming  on  water  place 
a  piece  of  phosphorus  and  ignite  it ;   invert  a  beaker  glass 

over  it  (Fig.  26).  What  becomes  of 
the  phosphorus  ?  When  the  latter  has 
ceased  burning,  restore  the  level  of 
the  water,  and  note  the  decrease  in 
the  volume  of  the  air.  Test  the  residual 
gas  with  a  burning  taper.  2.  Heat 
gently  in  a  small  flask  or  retort  a 
mixture  of  one  part  potassium  nitrite, 
one  part  ammonium  chloride,  one  part 
potassium  bichromate,  and  three  parts 

of  water ;   collect  the  gas  over  water.     Fill  five  bottles  with 

this  gas. 

(2)  Has  it  color,  taste,  odor  ?     Does  it  burn   or  support 
combustion  ?     Is  the  gas  heavier  than  air  ?     Does  it  unite 
readily  with  other  elements  ? 

(3)  Determine  the  Weight  of  a  Litre  of  Nitrogen. — A  round- 
bottomed  flask  is  fitted,  as  shown  in  Fig.   27.     Pour  about 
30  cc.  of  water  into  it,  and  insert  the  rubber  cork  to  the  mark. 
Boil  the  water,  while  the  clip  is  open,  until  all  the  air  has 
been  expelled  from  the  flask.     Steam  should  be  allowed  to 
escape  for  about  five  minutes.     Now  close  the  tube  with  the 
clip,  and  remove  the  flame.     Cool  and  weigh  the  flask.    Read 
the  temperature  and  barometric  pressure  in  the  balance-room. 

Connect  the  flask  with  the  tube,  b,  of  the  aspirator,  con- 
taining nitrogen,  and  arranged  as  in  Fig.  28.     The  rubber 


NITROGEN  GROUP — NITROGEN. 


37 


tube,  a,  is  made  to  dip  under  water,  and  the  clip  is  gradually 
opened,  allowing  nitrogen  to  enter  the  flask.  Now  raise  the 
vessel  containing  the  water  into  which  the  rubber  tube  dips, 
so  that  the  water  in  it  is  at  a  higher  level  than  that  in  the 
aspirator.  Close  the  clip.  Disconnect  the  flask  and  open  the 
clip  for  a  moment,  to  establish  atmospheric  pressure  in  the 
flask.  Weigh.  The  calculation  is  identical  with  that  given 
for  oxygen. 

What  is  the  ratio  between  the  weights  of  equal  volumes  of 
nitrogen  and  hydrogen  ? 

(4)  Is  air  a  chemical  compound  ? 

How  would  you  determine  the  weight  of  a  litre  of  air? 


FIG.  29. 


FIG.  28. 


r1 


FIG.  30. 


(5)  i.  Determination  of  the  Oxygen  in  Air  by  the  Pyrogallate 
Method. — 

At  the  atmospheric  temperature  and  pressure  measure  off 
50  cc.  of  air  in  the  Hempel  burette,  shown  in  Fig.  29.  Con- 
nect this  at  c  writh  the  capillary  of  a  Hempel's  compound 
pipette  (Fig.  30)  containing  an  alkaline  solution  of  pyrogallate 
of  potash.  Open  the  stop-cocks  and  transfer  the  air  to  the 
pipette  by  raising  the  tube,  a.  When  this  is  accomplished, 
and  the  capillary  of  the  pipette  is  filled  with  water  from  b, 
close  the  stop-cocks  again.  Disconnect  the  apparatus.  Shake 
the  pipette  for  several  minutes  so  as  to  bring  gas  and  absorbent 


FIG.  31. 


38  EXPERIMENTS   IN   GENERAL   CHEMISTRY. 

in  intimate  contact.  Reconnect  pipette  and  burette,  and 
force  the  residual  gas  into  the  latter.  Restore  atmospheric 
pressure  and  read  the  volume.  What  does 
the  loss  represent  ? 

2.  Explosion  Method. — To  40  cc.  of  air 
contained  in  the  burette  add  40  cc.  of  pure 
hydrogen.  Pass  this  mixture  into  the  Hem- 
pel  explosion  pipette  shown  in  Fig.  31. 
Close  the  stop- cock,  d,  and  the  clip,  c,  then 
connect  the  platinum  electrodes  with  an 
inductor  and  pass  a  spark.  What  takes  place  ?  Measure  the 
volume  of  the  gas  remaining.  How  much  of  the  contraction 
was  due  to  oxygen  ?  What  is  the  composition  of  the  gas  after 
the  explosion  ? 

(Study  Richter,  pp.  116-125.) 


FIG.  32. 


NITROGEN  AND  HYDROGEN. 
AMMONIA. 

(6)  Preparation. — Heat    an    intimate    mixture   of    finely 
powdered  ammonium  chloride  and  caustic  lime  in   a  flask 
(Fig.  32)  ;  conduct  the  evolved  gas  through 

a  tube  filled  with  small  pieces  of  lime,  and 
collect  it  in  jars  or  test-tubes  over  mercury. 
What  is  the  object  of  the  lime  in  the 
tube?  Why  can  you  not  dry  the  gas  by 
passing  it  through  sulphuric  acid  or  calcium 
chloride  ?  Why  should  it  be  collected  over 
mercury  ? 

(7)  Is  ammonia  gas  combustible  ?     Does 
it  support  combustion?     i.  Arrange  appa- 
ratus as  shown  in  Fig.  33.     a  is  a  piece  of  glass  tubing  four 
to  five  cm.  in  diameter;    its  lower  end  is  provided  with  a 
doubly  perforated  cork,  carrying  two  tubes  at  right  "angles. 


NITROGEN    GROUP NITROGEN   AND    HYDROGEN. 


39 


FIG.  33- 


A  slow  current  of  ammonia  is  made  to  pass  through  the  larger 
tube,  while  oxygen  is  introduced  by  means  of  the  smaller  tube. 
A  plug  of  cotton  serves  to  distribute  the 
latter  gas.  Carefully  regulate  the  flow  of 
the  gases  and  apply  a  lighted  taper  to  the 
escaping  ammonia.  Note  the  peculiar  ap- 
pearance of  the  flame.  2.  Heat  concen- 
trated ammonia  water  in  a  beaker  until 
there  is  an  abundant  disengagement  of  gas, 
then  conduct  a  rapid  current  of  oxygen 
through  the  liquid,  and  lower  a  glowing 
spiral  of  platinum  into  the  beaker  (as  in 
Fig.  34).  What  happens  ? 

Note  the  odor  of  ammonia  (caution  ?). 
Is  it  lighter  than  air?     Soluble  in  water  ? 

(8)  Prepare  an  Aqueous  Solution  of  Ammonia. 
What  are  its  properties  ? 

Add  red  litmus  to  some  of  the  solution  (?),  and  then 
neutralize  carefully  with  dilute  hydrochloric 
acid.  Evaporate  to  dryness.  Compare  the  pro- 
duct with  the  ordinary  ammonium  chloride. 
Test  it  for  chlorine  (?).  Heat  a  little  of  it  with 
sodium  hydroxide  (?).  Heat  another  portion 
on  a  platinum  foil  (?). 

(9)  Determine   the    Weight    of    a  Litre    or 
Ammonia. 

Fill  a  dry  flask  with  the  gas  by  upward  dis- 
placement, and  proceed  exactly  as  under  chlorine.  What  is 
the  density  of  ammonia  ? 

To  determine  the  quantitative  composition  of  ammonia, 
perform  experiments  i  and  2  on  pp.  130  and  131,  in  Richter. 
Write  out  summary.     (Read  Richter,  pp.  125-131.) 


FIG.  34. 


OF  THE 

UNIVERSITY 

Of 


40  EXPERIMENTS   IN   GENERAL  CHEMISTRY. 

NITROGEN  AND  THE  HALOGENS. 

(10)  Pour  a  saturated  aldoholic  solution  of  iodine  into  strong 
ammonia  water.  Collect  the  precipitate  on  a  filter  and  wash 
it  with  water.  Open  the  moist  filter ;  tear  it  into  small  pieces 
and  spread  these  on  a  board.  After  they  have  become  dry, 
touch  them  with  the  end  of  a  rod  (?).  Ask  for  instructions! 
(Read  Richter,  pp.  133-134.) 

NITROGEN  AND  OXYGEN. 

(n)  Nitrous  Oxide — N2O. — i.  Place  about  five  grams  of 
ammonium  nitrate  in  a  small  retort,  and  heat  gently.  Collect 
the  product  over  warm  water.  2.  Test  it  with  a  glimmering 
chip;  3.  with  burning  phosphorus;  4.  with  burning  sulphur. 
5.  Mix  equal  volumes  of  this  gas  and  of  hydrogen,  and  apply 
a  flame.  What  other  gas  does  it  resemble  in  its  properties? 
(Read  Richter,  pp.  215-216.) 

(12)  Nitric  Oxide — NO. — i.  Pour  dilute  nitric  acid  (sp. 
gr.  1.2)  upon  copper  turnings  contained  in  an  evolution  flask. 
Cool,  and  allow  the  red  fumes,  which  form  at  first,  to  escape ; 
then  collect  the  colorless  product  over  water.     2.  What  oc- 
curs when  this  gas  comes  in  contact  with  the  air?     Is  it  the 
oxygen  or  the  nitrogen  of  the  air  that  acts  upon  the  gas?     3. 
Apply  the  tests  given  under  (n)  to  this  gas  (?).     How  can  ni- 
tric oxide  be  distinguished  from  oxygen  ?     4.  Fill  a  cylinder 
with  nitric  oxide,  and  add  a  few  drops  of  carbon  dioxide,  shake 
well  and  bring  a  flame  to  the  mouth  of  the  vessel  (?).     5. 
Pass  a  current  of  nitric  oxide  into  a  strong  solution  of  ferrous 
sulphate.     What  occurs?     After  the  solution  has  become  sat- 
urated with  the  gas  heat  it  to  boiling  (?).     6.  Pass  the  gas 
into  a  solution  of  potassium  permanganate  (?). 

(13)  Nitrogen   Trioxide — N2O3 — (Read  Richter,  pp.   208- 
209.) 

Nitrous  Acid—RNQ*     (Richter,  p.  209.) 


NITROGEN    GROUP — NITRIC   ACID.  41 

(14)  Nitrogen  Tetroxide,  N2O4,  and  Dioxide,  NO2.— i.  Heat 
10  grams  of  dry  lead  nitrate  in  a  test-tube ;  condense  the 
escaping  vapors  in  a  receiver,  surrounded  by  a  freezing  mix- 
ture.    What  are  the  vapors,  and  what  is  the  condensed  liquid  ? 
Note  the  color.     2.  What  is  the  action  of  cold  water,  and  of 
aqueous  solutions  of  the  alkalies  upon   nitrogen  tetroxide? 
What  do  these  reactions  indicate  in  respect  to  the  composition 
of  this  compound  ?     (Richter,  pp.  210-211.)     3.  What  is  its 
action  upon  potassium  iodide? 

(15)  Nitrogen  Pentoxtde,  N2O5. — (Richter,  p.  208.) 

NITRIC  ACID.— HN03. 

1.  Preparation. — In    a  retort   heat  a   mixture  of  sodium 
nitrate  and  sulphuric  acid  in  proportions  corresponding  to 
the  equation  (?)  : 

NaN03  +  H2S04  ==  NaHSO4  +  HNO3. 

Collect  the  product  in  a  cold  receiver. 

2.  What  are  the  physical  properties  of  nitric  acid  ?     Color  ? 
Odor?     Action   on   litmus   (dilute   with   water)?     3.  What 
action  has  it  on  indigo  ?     Upon   the  skin  ?     4.  Notice  the 
effect  of  the  acid  upon  the  following  metals :  copper,  zinc, 
iron,  lead,  tin.     Write  the  reaction  for  each  one.     5.   Cover 
powdered  sulphur  with  the  acid,  and  warm  (?).     Dilute  with 
water,  filter,  and  test  the  liquid  with  barium  chloride  (?).     6. 
Add  a  few  drops  of  nitric  acid  to  a  solution  of  ferrous  sul- 
phate (?)  ;  warm  the  solution  (?). 

Problems. — i.  Required  one  cu.  m.  of  nitrogen.  How 
much  air  is  to  be  deprived  of  oxygen  ;  and  how  much  phos- 
phorus must  be  burned,  if  62  parts  of  the  latter  unite  with  80 
parts  of  oxygen  ? 

2.  How  much  nitric  acid,  containing  46  per  cent,  of  water, 
may  be  obtained  from  1,700  grams  of  sodium  nitrate,  and  how 
much  water  must  be  taken  ? 
6 


42  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

3.  How  many  grams  of  ammonia  will  be  absorbed  by  five 
litres  of  water,  if  the  latter  absorbs  500  times  its  volume  of  the 
gas  ?  4.  Ten  litres  of  water  having  absorbed  700  times  their 
volume  of  ammonia,  what  are  the  least  amounts  of  ammonium 
chloride  and  caustic  lime  necessary  for  producing  this  solu- 
tion? 

PHOSPHORUS.— P. 

(1)  i.  Determine  the  physical  properties  of  the  active  and 
the  red  varieties.   2.  Allow  a  small  piece  of  the  active  variety 
to  ignite  in  the  air.     Will  the  red  variety  do  this  ?     3.  Throw 
a  small  piece  of  the  yellow  variety  into  a  jar  of  dry  chlorine  (?). 
Repeat  with  the  red  variety  (?).     4.  Bring  a  small  dry  piece 
of  active  phosphorus  in  contact  with  iodine  (?).     5.  Heat  a 
flask  containing  a  small  piece  of  phosphorus  and  water  until 
the  former  is  melted,  then  pass  a  current  of  oxygen  through  a 
delivery  tube  into  the  melted  phosphorus (?).     Care!    (Study 
Richter,  pp.  134-137-) 

PHOSPHORUS  AND  HYDROGEN. 

(2)  Phosphine — PH3.    To  prepare  phosphine  arrange  appa- 

ratus  as  shown   in  Fig.  35. 
FlG-  35-  A  strong  solution  of  caustic 

soda  is  placed  in  the  flask,  to 
which  are  added  a  few  pieces 
of  phosphorus.  The  air  in 
the  flask  is  now  displaced  by 
passing  a  current  of  coal  gas 
through  it.  When  this  has 
been  done  close  the  clip,  a, 
and  gently  heat  the  contents 

of  the  flask.     What  becomes  of  the  gas  as  it  escapes  into  the 
air?     Write  the  reaction  involved. 
(Richter,  pp.  137-140.) 
Is  there  any  similarity  between  phosphine  and  ammonia  ? 


NITROGEN   GROUP — PHOSPHORUS   AND   OXYGEN.  43 

PHOSPHORUS  AND  THE  HALOGENS. 

(3)  i.  Pass  a  current  of  dry  carbon   dioxide  gas  into  a 
retort,  the  bottom  of  which  is  covered  with  dry  sand.     When 
all  the  air  has  been  expelled,  introduce  some  well-dried  pieces 
of  phosphorus,  and  replace  the  carbon  dioxide  by  a  stream  of 
dry  chlorine.     Connect  the  neck  of  the  retort  with  a  Liebig's 
condenser,  and  collect  the  product  in  a  receiver.   '  It  is  phos- 
phorus trichloride.     What  are  its  properties  ?     Pour  some  of 
it  into  water  (?). 

2.  Place  a  little  phosphorus  trichloride  in  a  dry  test-tube, 
and  pass  a  stream  of  dry  chlorine  upon  its  surface.  What  is 
the  result  ? 

PHOSPHORUS  AND  OXYGEN. 

(Richter,  pp.  217-222.) 

(4)  i.  Prepare  phosphorus  pentoxide,  P2O5,  by  burning  a 
carefully  dried  piece  of  phosphorus  under  a  dry  bell- jar.     2. 
Drop  a  portion  of  the  product  into  water  (?). 

(5)  Orthophosphoric  Acid,  H3PO±;  Metaphosphoric   Acid, 
HPO3;  and   Pyrophosphoric  Acid,  H4P2O7. — -How  are  these 
acids  obtained  ?     How  many  series  of  salts  are  derived  from 
them  ?  By  what  names  would  you  distinguish  the  different  salts  ? 

i.  Dissolve  some  disodium  hydrogen  phosphate,  Na-jHPO^, 
in  water  and  test  the  solution  with  silver  nitrate  and  ferric 
chloride.  What  do  you  observe  in  each  case?  2.  Dissolve 
fused  sodium  phosphate  in  water,  and  perform  the  same  tests 
with  its  solution.  3.  Heat  salt  of  phosphorus  (NaNH4HPO4) 
until  it  no  longer  effervesces;  cool,  crush  the  residue  in  a 
mortar,  and  dissolve  it  in  water.  How  does  this  solution 
behave  upon  treating  with  the  above  reagents?  4.  Acidify  a 
portion  of  the  last-named  solution  with  acetic  acid,  and  add 
a  solution  of  albumen  to  it.  Result  ? 

(6)  Phosphorus  Trioxide — P2O3,   and  Phosphorous  Acid — 
H3P03. 


44  EXPERIMENTS   IN    GENERAL   CHEMISTRY. 

Pour  phosphorus  trichloride  into  water.  Evaporate  the 
solution  to  syrupy  consistency  (?). 

(Study  Richter,  p.  219.) 

(7)  Hypophosphorous  Acid — H3PO2. 

Heat  pieces  of  phosphorus  in  a  porcelain  dish  with  a  mod- 
erately strong  baryta  solution  (see  p.  42).  When  no  more 
hydrogen  phosphide  is  formed,  cool,  filter,  and  pass  carbon 
dioxide  into  the  solution  until  it  shows  a  neutral  reaction  to 
litmus.  Toward  the  end,  the  solution  should  be  warmed. 
Filter  and  evaporate  to  suitable  concentration.  Hypophos- 
phite  of  barium  will  crystallize. 

How  may  the  free  acid  be  obtained  from  this  salt  ? 

ARSENIC.— As. 

(1)  Study  the  physical  and  chemical  properties  of  this  ele- 
ment.    (Richter,  pp.  143  and  144.)     Are  they  analogous  to 
those  of  phosphorus  ? 

i.  In  a  tube  of  hard  glass  heat  a  small  piece  of  arsenic  to 
redness.  Result?  2.  Heat  arsenic  with  the  oxidizing  flame 
upon  charcoal  (?).  3.  Dissolve  powdered  arsenic  in  strong 
nitric  acid  (?). 

ARSENIC  AND  HYDROGEN. 

(2)  Perform  Marsh' s  Jest  for  Arsenic* 

Arrange  the  appa- 
d       j      ratus   shown  in  Fig. 
36.     To  the  mixture 
of  zinc  and  dilute  sul- 
phuric acid  contained 
in  a,  add  a  small  por- 
tion of  the  solution  to 
be  tested  for  arsenic. 
The  liberated  gas  con- 
tains hydrogen  and  arsine.    It  is  passed  through  c,  filled  with 

*  Ask  for  instructions. 


NITROGEN   GROUP — ANTIMONY.  45 

calcium  chloride  (?),  and  then  through  d,  a  tube  of  hard 
glass,  contracted  at  several  places.  After  all  the  air  has  been 
expelled  from  the  apparatus,  ignite  the  hydrogen.  If  arsenic 
is  present  it  will  burn  with  a  bluish  white  flame,  and  white 
vapors  will  be  given  off.  Hold  a  cold  porcelain  plate  in  the 
flame  (?).  Heat  the  tube  d,  as  shown  in  the  figure  (?). 

Great  care  must  be  exercised  in  performing  this  test,  as  the 
arsine  gas  is  extremely  poisonous  ! 

ANTIMONY.— Sb. 

(i)  Study  this  element  in  the  same  manner  as  you  studied 
arsenic.  Distinguish  between  stibine  and  arsine. 

i.  Treat  the  metallic  mirrors  obtained  in  Marsh's  apparatus 
with  a  freshly  prepared  solution  of  hypochlorite  of  sodium : 
Arsenic  dissolves  readily,  while  antimony  is  scarcely  acted 
upon.  2.  Heat  a  piece  of  the  tube  in  which  a  mirror  -has 
formed,  in  the  flame  of  the  Bunsen  burner.  Dissolve  the  pro- 
duct in  dilute,  warm  hydrochloric  acid,  and  add  hydrogen 
sulphide  water  (?).  3.  Treat  the  spot  formed  upon  a  cold 
porcelain  plate  with  yellow  ammonium  sulphide,  and  evapo- 
rate the  solution  at  a  gentle  heat  (?). 

Problems. — (i)  How  much  phosphorus  can  be  obtained 
from  250  grams  of  bones?  (See  Richter,  p.  135.)  (2)  10  grams 
of  phosphorus  will  give  what  volume  of  phosphine  ?  (3)  What 
is  the  weight  of  the  product  remaining,  after  evaporating  a 
solution  of  10  grams  of  arsenic  in  nitric  acid. 


f  OF  THE        *  ^v 

(UNIVERSITY) 

*v  0p  J 


46         EXPERIMENTS  IN  GENERAL  CHEMISTRY. 

CHAPTER  VII. 

CARBON  GROUP— CARBON  AND  SILICON. 
CARBON.— C. 

(1)  How  many  allotropic  modifications  of  this  element  are 
known  ?     What  are  their  principal  properties  ?     In  a  rather 
wide  tube  collect  dry  ammonia  gas  (50—100  cc.)  over  mer- 
cury.    With  the  aid  of  a  forceps  insert  a  piece  of  charcoal, 
which  has  just  been   ignited.     What   happens?     2.  Boil  a 
dilute  litmus  solution  with  powdered  animal  charcoal ;  filter. 
Result?     3.  Substitute  indigo  for  the  litmus  in  the  preceding 
experiment  (?). 

4.  Determination  of  the  Composition  of  Coal. 
i.  Volatile  matter  and  coke.  Weigh  out  two  grams  of 
powdered  coal  in  a  platinum  crucible  provided  with  a  well- 
fitting  cover.  Heat  with  a  large 
flame,  until  the  escaping  gases  cease 
to  burn  between  the  lid  and  the  cruci- 
ble. A  blast  lamp  flame  is  applied 
for  a  minute  longer.  Cool  and 
weigh.  Loss  in  weight  represents  the 
volatile  matter.  The  residue  is  called 
coke. 

2.  Ash.     A  second  portion  of  coal 
(one  gram)  is  gently  heated  over  the 
Bunsen  flame,  until  the  volatile   constituents   are   expelled. 
The  heat  is  then  raised  and  the  lid  of  the  crucible  placed  in 
the  position  indicated  in  Fig.  37.     The  residue  is  the  ash. 
(Read  Richter,  pp.  151—152). 

CARBON  AND  HYDROGEN.' 

(2)  Methane  (Marsh  gas) — CH4. 

i.  Preparation. — Heat  a  dried  mixture  of  sodium  acetate 


CARBON    GROUP — CARBON    AND    OXYGEN.  47 

and  sodium  hydroxide  in  an  iron  tube.*  Collect  the  gas 
over  water.  Note  its  color,  odor,  and  taste.  Does  it  burn  ? 
2.  Mix  one  volume  of  it  with  seven  to  eight  times  its  volume 
of  air  and  explode  by  applying  a  flame.  (Ask  for  instruc- 
tions !  ) 

How  would  you  determine  the  molecular  weight  of  this 
compound  ? 

(3)  Make   a   eudiometric   combustion    of  one   volume   of 
marsh   gas   with   two   volumes   of  oxygen,   as   described   in 
Richter,  p.  121. 

(4)  Ethane— C2H6.     (Richter,  p.  154.) 

(5)  Acetylene — C2H2.     Light  a  Bunsen  burner  at  the  base 
and  turn  it  down,  so  that  the  flame  is  small.     Acetylene  can 
be  recognized,   among  the  products  of  combustion,   by  its 
characteristic  odor. 

(6)  CARBON  AND  THE  HALOGENS.     (Richter,  p.  161.) 

CARBON  AND  OXYGEN. 

(7)  Carbon  Dioxide — CO2. 

i.  Preparation. — Upon  pieces  of  marble,  contained  in  an 
evolution  flask,  pour  dilute  hydrochloric  acid  (i  HC1 :  1-2 
H2O).  Conduct  the  resulting  gas  through  water  and  through 
concentrated  sulphuric  acid.  It  may  be  collected  either  by 
downward  displacement  of  the  air,  or  over  mercury.  2.  Note 
color,  taste  and  odor  of  this  gas.  Is  it  soluble  in  water  ?  How 
does  its  weight  compare  with  that  of  air  ?  Does  it  burn  or  sup- 
port combustion?  3.  Conduct  a  current  of  carbon  dioxide 
into  a  solution  of  sodium  hydroxide,  evaporate  the  liquid, 
and  test  the  residue  for  sodium  carbonate  (?).  4.  To  differ- 
ent portions  of  the  sodium  carbonate  solution,  add  solutions 
of  magnesium  sulphate,  barium  chloride,  lead  nitrate  and  zinc 
sulphate. 

*  A  hard  glass  tube  will  answer. 


48  EXPERIMENTS   IN    GENERAL    CHEMISTRY. 

(Study  Richter,  pp.  230-235.) 

(8)  Carbon  Monoxide— CO. 

Preparation. — i.  In  a  tube  of  hard  glass  heat  zinc  dust  to 
faint  redness,  while  conducting  a  slow  current  of  carbon 
dioxide  over  it.  In  what  respect  does  the  product  differ 
from  carbon  dioxide.  2.  Heat  crystals  of  oxalic  acid  with 
concentrated  sulphuric  acid  in  a  flask,  and  wash  the  product 
with  a  sodium  hydroxide  solution.  Write  the  reaction.  Study 
the  properties  of  this  gas.  (Richter,  p.  235.) 

(9)  Carbon  Disulphide—C^. 

Perform  some  of  the  experiments  indicated  in  Richter,  p. 

237- 

(10)  CARBON  AND  NITROGEN. 

i.  In  a  dry  test-tube  heat  a  nitrogenous  carbon  compound 
with  a  small  piece  of  potassium.  Cool  and  add  water.  Po- 
tassium cyanide  is  formed  and  can  be  tested  with  silver  nitrate. 
2.  Convert  a  portion  of  the  potassium  cyanide  into  potassium 
sulphocyanide  by  evaporating  with  ammonium  sulphide.  Test 
with  ferric  chloride.  3.  To  a  solution  of  ferrous  sulphate  add 
potassium  ferrocyanide.  What  results  ?  4.  What  is  the  action 
of  the  ferrocyanide  upon  solutions  of  ferric  salts? 

(n)  Study  the  nature  of  flame.  Make  the  experiments 
described  in  Richter,  pp.  156-161. 

SILICON.— Si. 

(i)  Preparation. — Make  an  intimate  mixture  of  one  gram 
magnesium  powder  and  four  grams  of  finely  powdered  quartz- 
sand.  Heat  this  to  bright  redness  in  a  wide  tube  of  hard 
glass.  It  is  best  to  use  the  blast  lamp  for  this  purpose.  The 
part  of  the  tube  containing  the  mixture  should  be  rotated  in 
the  flame.  The  residue,  after  a  few  minutes'  heating,  is 
allowed  to  cool,  and  treated  with  water  containing  hydro- 
chloric acid.  The  product  consists  of  amorphous  silicon  and 
undecomposed  quartz.  2.  Test  the  action  of  the  following 


CARBON  GROUP — BORON.  49 

reagents  upon  silicon :  sulphuric,  nitric  and  hydrofluoric  acids, 
potash  solution  and  chlorine.     (Read  Richter,  p.  162.) 


SILICON  AND  OXYGEN. 

(2)  Silicon  Dioxide  (Silica,  Quartz) — -SiO2. 

i.  Test  its  solubility  in  the  various  acids  and  alkalies. 
2.  Fuse  a  mixture  of  one  gram  of  finely  powdered  quartz  with 
four  grams  of  sodium  carbonate,  in  a  platinum  crucible.  Dis- 
solve the  product  in  water.  3*.  To  a  portion  of  this  solution 
add  hydrochloric  acid,  and  evaporate  to  complete  dryness. 
Take  up  the  residue  with  water  and  filter  off  the  insoluble 
portion.  4.  To  another  portion  of  the  aqueous  solution  of 
the  fusion  add  ammonium  chloride  (?).  Make  a  bead  of 
salt  of  phosphorus  ;  bring  a  fragment  of  a  silicate  or  of  quartz 
into  it,  and  heat  in  the  blow-pipe  flame  for  a  few  minutes  (?). 

BORON.— B. 

(1)  Preparation  similar  to  that  of  silicon.     What  are  its 
properties  ?     Does  it  unite  directly  with  other  elements  ?     Is 
it  known  in  several  allotropic  modifications  ?     What  is  the 
valency  of  this  element  ? 

(Read  Richter,  pp.  243  and  244.) 

BORON  AND  OXYGEN. 

(2)  Boric  Acid—  H3BO3. 

i.  Dissolve  borax*  in  five  parts  of  boiling  water,  add  hydro- 
chloric acid  to  acid  reaction,  and  allow  to  cool.  What 
crystallizes  out  of  the  solution  ?  Dry  some  of  the  product 
by  pressing  it  between  filter  paper.  Test  its  solubility  in 
water  and  in  alcohol.  What  do  you  observe  on  igniting  the 
alcoholic  solution  ?  Moisten  a  piece  of  turmeric  paper  with 
an  aqueous  solution  of  boric  acid,  and  dry  at  a  gentle  heat. 
What  happens? 
7 


50  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

Problems. — (i)  How  much  carbon  dioxide  results  from  the 
combustion  of  12  grams  of  carbon?  (2)  How  much  carbon 
dioxide  will  an  indefinite  quantity  of  calcium  carbonate  give, 
when  acted  upon  by  4.666  grams  of  muriatic  acid,  containing 
30  per  cent,  of  pure  hydrogen  chloride  gas  ?  (3)  How  many 
cubic  decimeters  of  carbon  monoxide  can  be  obtained  from 
90  grams  of  oxalic  acid  ?  (4)  What  amount  of  silica  can  be 
obtained  from  two  grams  of  wollastonite  (CaSiO3)?  (5) 
What  is  the  theoretical  quantity  of  boric  acid  obtainable -from 
15  grams  of  borax  (Na.2B4O7  -f-  ioH2O)? 


METALS. 


FIG.  38. 


CHAPTER  VIII. 

METALS   OF    THE   ALKALIES— POTASSIUM,    SODIUM, 
[AMMONIUM]. 

POTASSIUM.— K. 

(1)  Preparation. — Arrange  apparatus  as  shown  in  Fig.  38. 
Into  a  tube  of  hard  glass,  introduce  a  porcelain  boat  contain- 
ing about  one  gram  of  a 

mixture    of    138    parts 

(one   mol.)    of  dry  (?) 

potassium        carbonate 

and  72  parts  (three  at.) 

of  magnesium  powder. 

Pass  a  current   of  dry 

hydrogen  over   it,  and 

after  all  the  air  has  been 

displaced  in  the  apparatus  (?),  light  the  escaping  gas ;  heat 

the  part  of  the  tube  surrounding  the  boat  to  incipient  redness. 

Observe  the  brilliant  metallic  mirror  which  is  formed,  and 

drive  it  away  from  the  boat  by  increasing  the  temperature :  it 

is  potassium.     Note  also  the  green  color  of  the  vapor  and 

the   violet   coloration    it  imparts   to  the  burning  hydrogen. 

What  is  the  residue  left  in  the  boat  ?     Test  its  reaction  with 

litmus  (?). 

Formulate  the  reaction  involved  in  this  method  of  prepara- 
tion. 

(2)  i.  Cut  a  piece  of  potassium  with  a  knife,  and  observe 


52  EXPERIMENTS    IN   GENERAL   CHEMISTRY. 

the  color  and  lustre  of  the  fresh  surface.  Care!  2.  To  as- 
certain whether  the  metal  is  fusible,  heat  a  small  piece  of  it  in 
a  stream  of  hydrogen.  3.  Is  it  heavier  or  lighter  than  water? 

(3)  i;  Expose  a  thin  slice  of  potassium  to  the  air.     What 
takes  place?     2.  Throw  a  small  piece  of  it  upon  water  (?). 
In  this  experiment  it  is  advisable  to  use  a  tall  beaker  and  to 
cover  the  same  with  a  glass  plate.     3.  What  is  the  action  of 
the  halogens  upon  potassium  ?     Ask  for  instructions. 

POTASSIUM   AND    OXYGEN. 

(4)  Preparation  of  Potassium  Hydroxide. — In  an  iron  vessel 
dissolve  50  grams  of  crystallized  barium  hydroxide,  Ba(OH)2, 
in  1 60  cc.  of  water.     Cautiously  add  a  hot  concentrated  solu- 
tion of  20  grams  of  potassium  sulphate  until  a  sample  of  the 
supernatant  liquid  is  no  longer  precipitated  by  either  potas- 
sium sulphate  or  barium  hydroxide.     Filter  rapidly  through  a 
plaited  filter,  and  evaporate  the  solution  in  an  iron  or  silver 
dish  over  a  large  flame.     Continue  heating  the  residue  till  it 
appears  in  a  state  of  quiet  fusion.     During  this  operation  pro- 
tect the  eyes  with  a  glass  plate.     Now  pour  the  product  upon 
a  clean  iron  surface,  and  while  still  warm  put  it  into  a  bottle 
provided  with  a  well-fitting   stopper.     Examine  its  fracture 
and  color.     Try  its  solubility  in  water  and  in  alcohol.     What 
is  the  reaction  of  the  aqueous  solution  with  litmus  ?     What  is 
an  alkali  ? 

Salts. 

(5)  Potassium  Chlorate.— KC1O3.     (See  p.  30). 

(6)  Potassium  Nitrate. — KNO3. — To   a   hot    concentrated 
solution  of  20  grams  of  sodium  nitrate  add  a  solution  of  18 
grams  of  potassium  chloride.     Boil.     What  separates  from  the 
warm  mixture?     What  crystallizes  from  the  mother  liquor  on 
cooling  ?    Recrystallize  the  latter  product  ?    Examine  its  crys- 
talline form.     Is  it  more  soluble  in  hot  than  in  cold  water  ? 
Explain  the  method  of  preparation. 


METALS    OF   THE   ALKALIES — SODIUM.  53 

(7)  Into  a  red-hot  platinum  crucible  throw  small  portions 
of  an  intimate  mixture  of  10  grams  of  potassium  nitrate  and 
i/^z  grams  of  charcoal  powder.     What  takes  place?     Write 
the  reaction.     What  is  gunpowder  ? 

Reactions. 

(8)  Use  potassium  nitrate  for  the  following  tests:  — 

i.  Place  a  little  of  the  salt  upon  the  end  of  a  clean  platinum, 
wire  and  introduce  it  into  a  non-luminous  flame.  What  color 
do  you  observe  ?  View  the  flame  through  a  cobalt  glass  (?). 
2.  To  the  aqueous  solution  of  the  potassium  salt  add  hydro- 
chloric acid  and  boil.  Concentrate  by  evaporation  and  add 
platinic  chloride.  What  is  the  composition  of  the  resulting 
precipitate  ?  Try  its  solubility  in  hot  and  in  cold  water, 
also  in  alcohol.  3.  To  the  concentrated  solution  of  the  salt 
add  a  saturated  solution  of  tartaric  acid ;  either  at  once,  or  on 
shaking,  a  white  crystalline  precipitate  appears  (?). 

SODIUM.— Na. 

(1)  How  is  this  metal  usually  prepared  ? 

(2)  Study  its  physical  and  chemical  properties  (Richter,  p. 
289).     Wherein  does  it  differ  from  potassium  ? 

(3)  Prepare  Sodium  Amalgam. 

To  500  grams  of  dry  mercury,  contained  in  a  Wedgwood 
mortar,  add  gradually  5-10  grams  of  sodium  in  thin  slices. 
Perform  this  operation  in  a  good  draught  chamber,  as  the 
union  of  the  two  metals  is  attended  with  the  evolution  of  light 
and  heat,  and  poisonous  vapors  are  given  off.  Stir  well  with 
the  pestle,  allow  to  cool,  and  transfer  the  product  to  a  well- 
stoppered  bottle.  What  is  its  action  on  water  or  dilute  sul- 
phuric acid  ? 

SODIUM   AND    OXYGEN. 

(4)  Preparation  of  Sodium  Hydroxide  Solution. 

Add  a  little  water  to  10  grams  of  fresh  quicklime  contained 


54  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

in  an  iron  (or  porcelain)  vessel.  Cover  the  latter,  and  in  a 
second  iron  pot  dissolve  25  grams  of  soda  ash  (Na2CO3),  using 
about  100  cc.  of  water.  Heat  the  solution  to  boiling;  stir 
the  quicklime — which  should  have  broken  up  to  a  white  powi 
der — with  enough  water  to  form  a  thin  paste  (milk  of  lime), 
and  add  this  gradually  to  the  boiling  liquid.  Stir  well  with 
an  iron  wire;  transfer  the  mixture  to  a  bottle;  cork,  and 
•allow  it  to  stand.  After  the  supernatant  liquid  has  become 
perfectly  clear,  decant  it  by  means  of  a  glass  siphon  filled  with 
water.  It  should  be  preserved  in  a  tightly  corked  bottle  (?). 
Test  a  few  drops  of  the  solution  with  barium  chloride  (?). 
What  should  the  solution  contain,  and  of  what  does  the  pre- 
cipitate, from  which  it  was  separated,  consist?  Write  the 
equation  representing  the  reaction. 

(5)  Determine  the  Amount  of Na  OH  contained  in  the  Solution. 

Measure  off  accurately  20  cc.  into  a  porcelain  dish  ;  add  a 
drop  or  two  of  phenolphthalein  solution,  and  dilute  with 
water.  From  a  burette  carefully  add  dilute  hydrochloric  acid 
until  the  red  color  has  just  disappeared.  Read  off  the  volume 
of  the  acid  used ;  it  is  the  exact  quantity  needed  to  neutralize 
the  alkali : — 

NaOH  -f  HC1  =  NaCl  +  H2O; 

that  is,  40  parts  (one  mol.)  of  sodium  hydroxide  require  36.5 
parts  (one  mol.)  of  hydrochloric  acid,  and  if  we  know  the 
weight  of  the  latter  contained  in  the  volume  of  the  dilute 
acid  consumed,  a  simple  proportion  will  give  the  weight  of 
the  alkali  in  20  cc.  of  the  solution.  The  strength  of  the  acid 
is  determined  as  follows:  In  a  porcelain  dish,  dissolve  1.06 
grams  of  pure  sodium  carbonate,  previously  ignited  and  accu- 
rately weighed  ;  add  a  little  phenolphthalein,  heat  to  boiling 
and  introduce  acid  from  the  burette  until  the  liquid  remains 
colorless  after  continued  boiling.  The  carbonate  is  then 
exactly  neutralized : — 

Na2C03  +  2HC1  =  2NaCl  +  CO2  -f  H2O. 


METALS   OF   THE   ALKALIES — SODIUM.  55 

It  takes,  therefore,  73  parts  of  hydrochloric  acid  for  106  parts 
of  sodium  carbonate.  Suppose,  now,  20  cc.  of  the  acid  had 
been  used  to  decolorize  the  indicator,  then  one  cc.  would 
equal  l$f  =  0.053  gram  of  sodium  carbonate  or  0.0365  gram 
of  hydrochloric  acid.  The  latter  number  is  the  standard  or 
strength  of  the  dilute  acid. 

The  phenolphthalein  takes  no  part  in  these  reactions  \  it 
merely  indicates  by  its  change  of  color  the  complete  neutrali- 
zation of  the  alkali.  Why  is  it  necessary  to  boil  the  solution 
when  the  acid  is  standardized  with  a  carbonate  ? 

Softs. 

(6)  Sodium  Chloride— NaCl. 

Purify  Common  Salt. — Grind  50  grams  of  salt  in  a  mortar 
with  150  cc.  of  water.     Filter  into  a  beaker,  and  conduct 
hydrochloric  acid  gas  into  the  solution,  as  shown  in  Fig.  39. 
Pure  salt  separates  out.     Collect  it  on 
a  platinum  cone,  remove  the  liquid 
with  the  aid  of  a  filter  pump,  and  dry 
the  salt  by  warming  it  in  a  porcelain 
dish,  while   stirring   it  with  a  glass 
rod. 

(7)  Sodium  Carbonate. — Na2CO3. 
Recrystallize  some  of  the  commer- 
cial carbonate.      Heat  a  portion  of 

the  product  in  a  porcelain  dish  ?    What  do  you  observe  ? 

formation  of  Sodium  Carbonate. 

(i)  Prepare  a  finely  divided  mixture,  consisting  of  six  parts 
of  dehydrated  sodium  sulphate  (Glauber's  salt),  four  parts  of 
chalk,  and  one  part  of  carbon.  Heat  this  upon  a  platinum 
foil  over  a  blast  lamp  until  it  fuses.  After  cooling,  place  the 
foil  in  a  porcelain  dish,  add  a  little  water,  and  heat  to  boil- 
ing. Filter  the  solution  into  a  test-tube,  and  to  a  portion  of 
the  filtrate  add  hydrochloric  acid.  What  happens?  It  indi- 


56  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

cates  the  presence  of  what  ?  In  a  second  portion  of  the  filtrate 
add  hydrochloric  acid.  In  the  mouth  of  the  test-tube  suspend 
a  strip  of  filter  paper  previously  moistened  with  lead  acetate. 
What  happens?  Explain.  This  experiment  maybe  said  to 
illustrate  what  technical  process  ? 

(2)  Make  a  cold  saturated  solution  of  ammonium  carbonate 
by  shaking  the  finely  divided  commercial  salt  repeatedly  with 
cold  water.  A  saturated  sodium  chloride  solution  is  prepared 
in  the  same  manner.  Conduct  a  current  of  carbon  dioxide 
into  the  ammonium  carbonate  solution,  and  occasionally 
shake  the  vessel  containing  the  solution.  In  the  course  of 
half  an  hour  mix  the  two  liquors,  shake  the  mixture  vigor- 
ously, run  in  the  carbon  dioxide  again,  and  alternate  these 
operations  until  a  crystalline  precipitate  separates.  What  is 
it  ?  Dissolve  a  portion  of  it  in  water,  add  hydrochloric  acid. 
Dip  a  clean  platinum  wire  into  the  solution  and  hold  it  in  a 
colorless  Bunsen  flame.  What  name  is  given  to  the  technical 
process  based  on  this  principle  ? 

Reactions. 

(8)  Use  the  purified  chloride  for  the  tests,  i.  What  color 
do  sodium  salts  give  to  the  flame?  2.  Mix  a  drop  of  the 
aqueous  solution  with  10  drops  of  a  platinic  chloride  solution 
on  a  watch-glass.  Evaporate  very  carefully  to  a  small  volume. 
On  cooling,  a  red-colored  salt  crystallizes  out  in  long  mono- 
clinic  needles  (?).  Is  it  soluble  in  water?  in  alcohol?  3.  Are 
there  any  salts  of  sodium  which  are  not  soluble  in  water? 
Can  compounds  of  sodium  be  precipitated  by  any  reagent  ? 

AMMONIUM. 

(i)  What  is  the  composition  of  ammonium?  Can  it  be 
obtained  in  a  free  state?  (See  Richter,  p.  299.)  To  a  warm 
concentrated  solution  of  ammonium  chloride,  contained  in 
a  large  dish,  add  sodium  amalgam  (see  p.  53).  What 


METALS    OF    THE   ALKALIES — AMMONIUM.  57 

occurs?     Hold  a  piece  of  reddened  litmus  paper  over  the 
dish  (?). 

(2)  Dissolve  commercial  sal  ammoniac  in  a  little  water, 
add  ammonia  in  slight  excess,  warm,  filter  if  a  precipitate  is 
formed,    and    evaporate   to    crystallization ;    stir   constantly. 
Ammonium  chloride  is  thus  obtained  in  the  form  of  a  fine 
powder. 

Reactions. 

(3)  i.  On  a  piece  of  platinum  foil  heat  successively  small 
portions  of  the  chloride,  the  sulphate,  and  the  nitrate.    What 
occurs  in  each  case?    2.   Mix  a  little  ammonium  chloride  with 
burnt  lime  in  a  small  mortar.     Note  the  odor  of  the  escaping 
gas  and  its  reaction  with  litmus.     3.   Heat  a  small  portion  of 
ammonium  chloride  with  a  caustic  soda  solution.     What  is 
given  off?     Explain  the  action  of  strong  bases  upon  ammo- 
nium salts.     4.  Add  platinic  chloride  to  a  solution  of  ammo- 
nium chloride.     Result?     5.  To  a  concentrated  solution  of 
the  ammonium  salt  add  tartaric   acid  and  shake  the  mix- 
ture (?).     6.   Do  compounds  of  ammonium  impart  a  color  to 
the  flame? 

Compare  the  metals  of  the  alkalies  with  each  other.  How 
can  the  compounds  of  potassium,  sodium,  and  ammonium  be 
distinguished  ? 

Problems. — i.  How  much  potassium  nitrate  is  theoretically 
obtainable  from  two  kilos  of  Chili  saltpetre  of  97  per  cent., 
and  what  amount  of  sylvite  containing  98  per  cent,  of  potas- 
sium chloride  is  required?  2.  Suppose  that  75  cc.  of  dilute 
nitric  acid  were  required  to  saturate  50  cc.  of  a  potash  lye; 
further,  that  10  cc.  of  the  acid  neutralized  1.06  grams  of 
sodium  carbonate,  what  amount  of  caustic  potash  would  the 
lye  contain?  3.  In  the  valuation  of  a  pearl  ash  (impure 
K2CO3),  29.1  cc.  of  a  sulphuric  acid  were  used  to  neutralize 
five  grams  of  the  sample;  the  acid  contained  98  grams  of 
8 

f  -,}£     y  ^ 

(XTNIVERSITT 


58  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

sulphuric  acid  per  litre ;  calculate  the  percentage  of  impurities 
in  the  product.  4.  Required  the  minimum  amount  of  marble 
that  should  be  burnt  to  liberate  the  ammonia  from  50  grams 
of  ammonium  nitrate. 


CHAPTER  IX. 

METALS    OF   THE   ALKALINE    EARTHS— CALCIUM, 
STRONTIUM,  BARIUM. 

CALCIUM.— Ca. 
CALCIUM    AND    OXYGEN. 

(1)  i.  Ignite  two  grams  of  powdered  marble  in  a  platinum 
crucible  to  the  highest  temperature  obtainable  with  the  aid 
of  the  blast  lamp.     Continue  this  for  15  minutes,  occasionally 
stirring  the  mass  with  a  platinum  wire  ;  what  is  the  residue  ? 
Explain  the  reaction.     2.  Add  about  five  cc.  of  water  to  the 
product.     What  do  you  observe?     Test  the  reaction  of  the 
product  with  litmus  paper. 

(2)  i.  Prepare  Lime-Water.— -To  the  slaked  lime  obtained 
from  twenty  grams  of  quicklime  (see  p.  54)  add  one  litre  of 
water  ;  transfer  the  mixture  to  a  bottle.     Cork  tightly,  shake 
and  allow  to  stand.     When  the  solution  has  become  clear, 
draw  it  off  by  means  of  a  siphon  ?     What  does  it  contain  ? 
Of  what  does  the  undissolved  portion  consist  ?     2.  Place  a  por- 
tion of  the  lime-water  on  a  watch  glass  and  expose  to  the  air  (?). 
3.  Through  a  second  portion  blow  air  from  your  lungs  (?).     4. 
Conduct  a  stream  of  carbon  dioxide  through  a  third  portion 
and  observe  carefully  the  successive  changes.     Explain  them. 
5.  What  takes  place  upon  boiling  the  clear  solution  which  is 
obtained  as  the  final  product  in  the  preceding  experiment  ? 


METALS    OF   THE    ALKALINE    EARTHS — STRONTIUM.  59 

Salts. 

(3)  Calcium  Chloride. — CaCl2. 

i.  Evaporate  some  of  the  spent  acid  of  a  carbon  dioxide 
generator  to  dryness.  What  is  the  residue?  2.  Expose  a 
little  of  the  salt  to  the  air  (?).  3.  What  use  have  you  made  of 
calcium  chloride  previously  ?  4.  Prepare  porous  calcium  chlo- 
ride (CaCl2  -f  2H2O).  Dissolve  the  residue  obtained  in  i  in 
lime-water,  filter,  and  neutralize  exactly  with  hydrochloric 
acid.  Evaporate  the  filtrate  to  dryness  in  a  porcelain  dish, 
and  heat  the  residue  for  some  time  on  the  sand-bath.  The 
solution  of  the  product  must  show  a  neutral  reaction. 

(4)  Calcium  Hypochlorite. — Ca(ClO)2.     (See  p.  30.) 

(5)  Calcium  Sulphate.— CaSO*. 

i.  Carefully  heat  a  few  grams  of  gypsum  in  a  porcelain  dish 
until  the  water  of  crystallization  is  completely  expelled. 
Pulverize  the  residue.  What  happens  when  it  is  made  into  a 
paste  with  water  and  allowed  to  stand  ? 

Reactions. 

Use  the  pure  calcium  chloride  for  the  following  tests : — 
i.  Introduce  a  small  portion" of  the  salt  into  the  Bunsen 
flame  by  means  of  a  platinum  wire  (?).  2.  To  the  aqueous 
solution  add  ammonium  carbonate.  Result?  3.  To  another 
portion  add  dilute  sulphuric  acid.  What  is  the  composition 
of  the  precipitate?  Why  does  it  not  form  in  very  dilute 
solutions  ?  4.  Add  ammonia  water  and  ammonium  oxalate 
to  the  filtrate  from  the  calcium  sulphate. 

STRONTIUM.— Sr. 

Reactions. 

i.  What  color  is  imparted  to  the  Bunsen  flame  by  com- 
pounds of  this  element?  2.  Add  a  gypsum  solution  to  the 
solution  of  a  strontium  salt  (?). 


60  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

BARIUM.— Ba. 

Reactions. 

i.  Observe  what  color  barium  compounds  give  to  the  flame. 
Moisten  the  sample  with  hydrochloric  acid  before  heating  it 
(?).  2.  To  a  portion  of  the  aqueous  solution  of  the  chloride 
add  ammonium  carbonate.  What  results?  3.  Add  dilute 
sulphuric  acid  to  a  second  portion  (?). 


Point  out  how  the  elements  of  this  group  may  be  dis- 
tinguished (a)  from  those  of  the  preceding  group ;  (£)  from 
each  other. 

Problems. — i.  How  much  nitric  acid  of  20  per  cent,  will 
effect  the  solution  of  one  gram  of  Iceland  spar  (CaCO3)  ? 
How  much  carbon  dioxide  is  given  off,  and  what  volume 
would  it  occupy  at  20°  C.  under  a  pressure  of  750  mm.  ?  2. 
Suppose  .5  gram  of  sulphur  were  dissolved  in  nitric  acid,  what 
quantity  of  barium  chloride  must  be  added  until  it  ceases  to 
produce  a  precipitate?  3.  One  gram  of  a  mineral  consisting 
of  the  carbonates  of  calcium,  strontium,  and  barium,  in  the 
proportion  of  their  molecular  weights,  will  leave  what  weight 
of  the  mixed  sulphates  on  treating  and  evaporating  with  an 
excess  of  sulphuric  acid  ? 


CHAPTER  X. 
MAGNESIUM    GROUP— MAGNESIUM,  ZINC,  CADMIUM. 

MAGNESIUM.— Mg. 

(i)  Examine  the  metal  in  the  forms  of  ingot,  ribbon  and 
powder.  Note  its  color,  lustre  and  specific  gravity.  2.  Intro- 
duce a  piece  of  the  ribbon  into  the  flame  with  the  forceps  (?). 


MAGNESIUM    GROUP — MAGNESIUM.  6 1 

What  is  the  product  ?     3.  Treat  a  piece  of  the  ribbon  with 
dilute  sulphuric  acid.     Reaction  ? 

Salts. 

(2)  Magnesium  Chloride. — MgCl2. 

Prepare  the  ANHYDROUS  salt. — Dissolve  about  50  grams  of 
the  crystallized  (?)  chloride  and  50  grams  of  ammonium  chlo- 
ride in  as  little  water  as  possible.  Evaporate  to  dryness  in  a 
porcelain  dish.  Reduce  the  mass  while  hot  to  small  pieces  in 
a  mortar,  dry  it  carefully,  so  as  to  remove  every  trace  of 
moisture.  It  is  best  to  do  this  by  heating  small  portions  of 
the  material  in  a  porcelain  crucible  until  it  no  longer  sinters. 
A  small  sample  should  not  give  off  moisture  when  heated  in  a 
dry  test-tube.  Be  careful  also  to  prevent  re-absorption  of 
moisture.  Quickly  transfer  the  warm  powder  to  a  platinum 
crucible  provided  with  a  well-fitting  cover.  Heat,  at  first 
gently,  to  expel  the  ammonium  chloride,  then  increase  the 
temperature  until  the  mass  is  in  a  state  of  quiet  fusion.  It  is 
the  anhydrous  salt  which,  being  extremely  hygroscopic,  should 
be  preserved  in  a  tightly-stoppered  bottle.  It  should  dissolve 
in  water  to  a  clear  liquid. 

Why  cannot  the  anhydrous  chloride  be  obtained  by  evapo- 
ration of  the  aqueous  solution  ? 

(3)  Magnesium  Sulphate. — Mg  SO4  -}-  7H2O. 
Recrystallize  some  of  the  commercial  salt.     What  is  the 

form  of  the  crystals  ?     Taste  ? 

(4)  Reactions. 

i.  Heat  a  portion  of  the  sulphate  or  chloride  on  a  platinum 
wire  in  the  Bunsen  flame ;  moisten  with  cobalt  nitrate  solu- 
tion and  heat  again.  A  pink- colored  mass  results.  2.  Add 
some  caustic  soda  to  a  little  of  the  solution  of  the  chloride  (?). 
The  resulting  precipitate  dissolves  on  addition  of  an  ammo- 
nium salt  (?).  3.  Mix  a  second  portion  of  the  chloride  solu- 


62  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

tion  with  ammonia  water  and  ammonium  chloride,  add  disod- 
ium  hydrogen  phosphate  and  agitate  the  liquid.  What  is  the 
composition  of  the  precipitate  ?  Examine  it  with  the  aid  of 
a  lens. 

ZINC.— Zn. 

(1)  How  is  this  metal  obtained  from  its  ores? 

(2)  Study  the  physical  and  chemical  properties  of  zinc  (see 
Richter,  p.  320).     i.  Treat  a  small  piece  of  pure  metal  with 
dilute  sulphuric  acid  (?).     2.  Repeat  this  experiment,  substi- 
tuting the  impure  commercial  metal.     What  difference    do 
you  observe  ?     What  causes  it  ? 

(3)  Granulate  Commercial  Zinc. — Melt   100  grams  of  the 
metal  in  a  well-covered  Hessian   crucible.     The  blast  lamp 
may  be  used  for  this  purpose,  but  it  is  better  to  perform  the 
operation  in  a  wind  furnace.     The  crucible  is  then  removed 
from  the  source  of  heat,  and  allowed  to  cool  until  the  molten 
metal  no  longer  takes  fire  when  the  cover  is  lifted.     Pour  the 
metal,  in  a  thin  stream,  into  a  pail  filled  with  cold  water. 
Drain  the  product  and  dry  at  a  moderate  heat. 

Salts. 

(4)  Zinc  Sulphate.— -Zn  SO4  -f-  7H2O.  (See  p.  14).     i.  Pre- 
pare some  of  this  salt  and  recrystallize  it  carefully  from  water. 
2.  Examine  the  crystals.     What  other  salt  have  you  prepared 
that  exhibits  similar  forms?     Is  there  any  analogy  in  the  com- 
position of  the  two  salts  ? 

Reactions. 

(5)  i.  Heat  a  small  piece  of  zinc  on  charcoal  in  the  oxidiz- 
ing flame  (?).     2.   Moisten  the  incrustation  obtained  with  a 
drop  of  cobalt  nitrate,  and  heat  again.     Result?     3.  To  a 
solution  of  zinc  sulphate  add  ammonium  sulphide.     What  is 
the  color  of  the  precipitate?     Try  its  solubility  in  dilute  hy- 
drochloric acid  and  in  HC2H3O2  (acetic  acid).     4.  Study  the 


MERCURY.  63 

action  of  caustic  alkalies,  e.  g.   caustic  soda,  upon  the  zinc 
solution. 


How  could  you  distinguish  between  zinc  and  magnesium  ? 
What  differences  are  there  between  this  and  the  preceding 
groups  j> 

Problems.  —  i.  What  is  the  strength  of  a  sulphuric  acid  of 
which  20  cc.  dissolve  exactly  .048  gram  of  magnesium?  2. 
Suppose  it  was  found  that  one  gram  of  zinc  gave  with  sul- 
phuric acid,  325  cc.  of  hydrogen  at  16°  C.  and  755  mm., 
and,  further,  that  .369  gram  of  magnesium  produced  the  same 
amount  of  the  gas.  Knowing  the  atomic  weight  of  magne- 
sium to  be  24,  and  remembering  that  the  two  sulphates  are 
isomorphous,  how  is  it  possible  to  deduce  the  atomic  weight 
of  zinc  from  the  data  given  ? 


CHAPTER  XI. 
MERCURY,  COPPER,  SILVER,  GOLD. 

MERCURY.— Hg. 

(1)  Study   the  physical   and   chemical   properties   of  the 
metal.     Wherein  does  it  differ  from  the  other  metals? 

MERCURY   AND    OXYGEN. 

(2)  Mercuric  Oxide. — HgO. 

How  is  this  substance  prepared  ?  What  is  its  behavior  on 
heating? 

Mix  a  little  powdered  sulphur  with  dry  sodium  carbonate 
and  mercuric  oxide.  Ignite  the  mixture  in  a  dry  test-tube. 
Extract  the  residue  with  water,  filter,  acidify  with  hydrochloric 
acid  and  add  barium  chloride.  What  has  become  of  the 
oxide  of  mercury  in  this  experiment? 


64  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

Salts. 

(3)  Mercurous  Nitrate. — HgNO3. 

An  excess  of  metallic  mercury  (use  10-15  grams)  is  treated 
in  the  cold  with  moderately  strong  nitric  acid  until  the  forma- 
tion of  crystals  is  no  longer  noticeable.  Redissolve  the  crys- 
tals by  warming,  filter,  and  allow  to  crystallize. 

To  prepare  a  solution  of  the  salt  take  it  up  with  water  acidu- 
lated with  nitric  acid  (?). 

(4)  Mercuric  Chloride.—  HgCl2. 

Dissolve  about  five  grams  of  metallic  mercury  in  aqua  regia. 
Evaporate  to  dryness  on  a  water  bath.  Place  the  residue  into 
a  small  dry  flask,  cover  the  latter  with  a  watch-glass,  and  heat 
cautiously  on  a  sand-bath.  What  is  the  sublimate  formed  in 
the  upper  part  of  the  flask  ?  Dissolve  it  in  four  parts  of  boil- 
ing water  and  allow  to  crystallize. 

Reactions. 

(5)  Mercurous  Compounds. — Use  the  solution  of  the  nitrate. 
i.  Add  a  few  drops  of  hydrochloric  acid  to  two  or  three  cc. 
of  the  solution.     What  takes  place?     Filter,  and  add  ammo- 
nia water  to  the  precipitate  (?).     2.  Add  stannous  chloride 
to  another  portion  of  the  nitrate  solution  (?).     3.  In  a  third 
portion  immerse  a  strip  of  copper  foil.     Examine  the  stain  on 
the  metal ;  is  it  changed  when  you  hold  it  in  the  flame  ? 

(6)  Mercuric  Compounds. — The  chloride  will  answer  for  the 
tests. 

i.  Pass  hydrogen  sulphide  through  a  dilute  solution  and 
observe  the  gradation  of  colors  through  which  the  precipitate 
passes.  What  is  the  final  product  ?  2.  Add  stannous  chloride, 
drop  by  drop,  to  the  mercury  solution.  Explain  the  changes 
which  occur. 

COPPER.— Cu. 

i.  Preparation. — Ignite  the  pure  oxide  in  a  current  of  dry 
hydrogen  (see  p.  16).  Examine  the  color  and  the  lustre  of 


JKIVIIRSITT 


COPPER.  65 

the  product  ;  test  its  solubility  in  hydrochloric  acid,  sulphuric 
acid  (both  strong  and  dilute),  and  nitric  acid.  Write  equa- 
tions representing  the  reactions. 

Salts. 

(2)  Copper  Sulphate.—  -CuSO,  +  5H2O. 

To  12  grams  of  copper  in  a  flask  add  45  grams  of  concen- 
trated sulphuric  acid,  and  heat.  When  the  metal  has  com- 
pletely disappeared  and  the  gas  (?)  ceases  to  be  given  off, 
allow  to  cool,  place  the  white  crystalline  residue  (?)  into  a 
porcelain  dish,  rinse  the  flask  with  hot  water.  Now  add  a  few 
drops  of  nitric  acid  to  the  hot  water  solution,  and  filter. 
From  the  filtrate  the  sulphate  crystallizes  on  standing.  Re- 
crystallize  the  product. 

Does  this  salt  suffer  decomposition  on  exposure  to  the 
atmosphere  ?  Heat  a  small  quantity  in  a  porcelain  crucible, 
first  moderately,  then  more  strongly  (?). 

(3)  Sulphate   of    Copper  and  Potassium.  —  CuK2(SO4)2  -f- 
6H2O. 

Prepare  solutions  of  10  grams  of  blue  vitriol  and  seven 
grams  of  potassium  sulphate,  both  saturated  at  70°.  The 
latter  should  also  contain  a  few  drops  of  sulphuric  acid.  Mix 
the  solutions  :  on  cooling  the  double  salt  separates  in  whitish- 
blue  crystals.  Examine  their  form. 

Re-actions. 

(4)  Use  either  of  the  salts  you  have  prepared. 

i.  Mix  a  little  of  the  salt  with  sodium  carbonate,  and  heat  on 
charcoal  in  the  reducing  flame  (?).  2.  Make  a  borax  bead 
and  dissolve  a  minute  quantity  of  a  copper  compound  in  it. 
What  color  does  it  give  (a)  in  the  oxidizing  flame?  (^)  in 
the  reducing  flame  ?  (c}  when  the  bead  is  reduced  with  a 
small  piece  of  tin  ?  3.  Through  a  dilute  copper  solution  pass 
hydrogen  sulphide.  Is  the  resulting  precipitate  soluble  in 
9 


66  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

hydrochloric  acid  or  in  nitric  acid?  4.  Add  ammonia,  drop 
by  drop,  to  the  solution.  What  changes  do  you  observe?  5. 
To  a  portion  of  the  very  dilute  solution  add  potassium  ferro- 
cyanide  (?). 

(5)  To  a  solution  of  copper  sulphate  in  a  porcelain  dish  add 
a  small  piece  of  zinc.     Allow  to  stand  over  night.     Note  the 
result.     Has  the  zinc  disappeared?    Does  the  solution  contain 
any  of  this  metal  ?     In  what  form  ?     Where  is  the  copper  ? 

(6)  Repeat  the  experiment,  weighing  the  copper  sulphate 
(.1  gram)  and  the  zinc  (.5  gram).     Add  hydrochloric  acid  in 
quantity  sufficient  to  insure  the  entire  solution  of  the  zinc, 
collect  the  copper  on  a  filter,  wash  with  alcohol,  dry,  heat 
gently  and  weigh   it  in  a  porcelain  crucible.     The  filtrate 
should  be  colorless. 

Compare  the  weight  of  the  metallic  copper  obtained  with 
that  of  the  zinc  employed  (?).  How  does  the  found  copper 
accord  with  the  calculated  amount  of  that  metal  in  .5  gram 
of  CuSO4.5H2O? 

Repeat  the  experiment,  using  cadmium  in  place  of  zinc. 
Compare  the  weights  of  the  metals  as  before.  What  deduc- 
tion can  you  make  ? 

Dissolve  one  gram  of  pure  copper  sulphate  in  250  cc.  of 
water ;  to  this  add  one  gram  of  ammonium  sulphate  and  10  cc. 
of  ammonia  water  (specific  gravity  0.96).  Transfer  this  solu- 
tion to  a  platinum  dish,  connect  the  latter  with  the  cathode 
(?)  of  a  battery  consisting  of  from  four  to  six  gravity-cells, 
and  in  the  solution  suspend  a  flat-spiral  of  platinum  in  connec- 
tion with  the  anode  (?)  of  the  battery.  As  the  current  con- 
tinues to  act  what  changes  occur?  How  will  you  determine 
when  the  reaction  is  at  an  end?  When  this  point  has  been 
reached,  add  sodium  acetate  to  the  liquid,  interrupt  the  cur- 
rent, pour  out  the  solution  and  wash  the  deposit  of  copper 
first  with  warm  water,  then  with  alcohol  (?),  and  after  careful 
drying,  weigh.  What  is  electro-plating? 


SILVER.  .       67 

SILVER.— Ag. 

(1)  Prepare  Pure  Silver  from  a  Coin. 

Dissolve  a  25 -cent  piece  in  nitric  acid  of  specific  gravity 
1.2.  filter  (?),  and  evaporate  the  blue  (?)  solution  to  dryness. 
Fuse  the  residue  till  it  blackens,  extract  with  250  cc.  of  water ; 
filter.  Now  add  ammonia  in  large  excess,  and  then,  cautiously, 
a  sodium  bisulphite  solution  (of  about  40  per  cent.)  until  on 
boiling  a  small  portion  of  the  liquid,  it  is  completely  decolor- 
ized. 

The  greater  part  of  the  silver  separates  from  the  solution  on 
standing  in  the  cold ;  it  is  well  crystallized.  The  remainder 
may  be  precipitated  by  warming  to  70°.  Digest  the  product 
with  strong  ammonia  (?),  wash,  dry  and  ignite  it. 

Examine  the  metal  carefully.  What  are  its  physical  and 
chemical  characteristics  ? 

SILVER   AND    SULPHUR. 

( 2 )  Silver  Sulphide.  —  Ag2S. 

Into  a  dilute  solution  of  silver  nitrate  (se«  next  experiment), 
containing  about  two  grams  of  the  metal,  pass  hydrogen  sul- 
phide. When  the  liquid  smells  of  the  gas,  filter  off  the  black 
precipitate,  wash  it  with  water  and  dry  at  100°. 

Salts. 

(3)  Stiver  Nitrate.—  AgNO3. 

Dissolve  the  silver  obtained  in  (i)  in  dilute  nitric  acid  and 
evaporate  to  dryness  on  the  water  bath.  Dissolve  the  residue 
in  80  cc.  of  distilled  water,  and  preserve  the  solution  in  a  dark 
bottle  (?).  What  is  its  reaction. with  litmus? 

Reactions. 

(4)  i.  Compounds  of  silver  on  charcoal  before  the  blow- 
pipe give  a  white  metallic  globule  (?).      2.   To  a  silver  solu- 


68       .  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

tion — use  the  nitrate — add  hydrochloric  acid.  Collect  the 
precipitate  on  a  small  filter,  wash,  dissolve  it  in  ammonia,  and 
add  an  excess  of  nitric  acid  to  the  solution  (?).  Explain 
these  reactions.  3.  Expose  a  small  portion  of  the  chloride  to 
direct  sunlight.  Any  change  ?  What  practical  application  is 
made  of  this  reaction?  (Read  Richter,  p.  344.)* 

(5)  Place  strips  of  the  metals  zinc,  iron,  tin,  lead,  and  cad- 
mium in  a  solution  of  silver  nitrate.  What  is  the  result  in 
each  case  ?  Explain. 

GOLD.— Au. 

(1)  Prepare  pure  gold  from  the  commercial  metal.     Frag- 
ments of  jewelry  or  a  gold  coin  may  be  used.     A  weighed 
quantity  of  material  is  placed  in  a  small  flask  and  covered  with 
concentrated  hydrochloric  acid.     Heat  is  applied,  while  small 
quantities  of  nitric  acid  are  continually  added  from  time  to 
time.     The  resulting  solution  is  evaporated  on  the  water-bath, 
care  being  taken  to  exclude   dust.     Dissolve  the  residue  in 
water,  filter  (?),  and  add  a  large  excess  of  a  ferrous  chloride 
solution  to  the  filtrate.     Upon  heating,  metallic  gold  separates 
as  a  reddish-brown    powder.     Allow   to   settle   and    decant. 
Extract  repeatedly  with  dilute,  boiling  hydrochloric  acid,  and 
collect  the  gold  on  a  filter.     Incinerate  the  latter  in  a  porce- 
lain crucible  and  weigh  the  product.     How  could  you  distin- 
guish the  metal  gold  from  mercury,  silver,  and  copper  ? 

Reactions. 

(2)  i.  .Dissolve  a  small  piece  of  gold  (or  of  a  substance 
containing  gold)  in  aqua  regia,  concentrate  the  solution  at  a 
gentle  heat  and  pour  it  into  a  porcelain  dish.     Add  a  solution 
of  ferric  chloride  to  a  stannous  chloride  solution   until  the 
latter  is  permanently  yellow.     After  diluting,  dip  a  glass  rod 

*If  practicable,  the  instructor  should  here  show  and  explain  the  prepar- 
ation of  a  photographic  negative. 


ALUMINIUM.  69 

into  this  and  then  into  the  gold  solution.  A  purple  streak 
(purple  of  Cassius)  is  formed.  2.  Add  ferrous  sulphate  to 
some  of  the  gold  chloride  solution  (?). 


In  what  respects  do  the  members  of  this  group  differ  from 
each  other,  and  how  can  they  be  distinguished  from  the 
metals  of  the  preceding  groups  ? 

Problems. — 0.5  gram  of  mercuric  oxide  gave  on  ignition 
with  carbon  0.463  gram  of  metallic  mercury;  the  specific 
gravity  of  the  vapor  of  mercuric  chloride  referred  to  hydrogen 
was  found  to  be  135.5.  What  is  the  atomic  weight  of  mer- 
cury? 2.  The  molecule  of  mercury  contains  how  many 
atoms,  if  the  vapor  density  equals  100?  3.  On  analysis  a 
chalcocite  was  found  to  contain  20.15  per  cent,  of  sulphur 
and  79.85  per  cent,  of  copper.  Deduce  the  molecular  formula 
of  the  mineral.  4.  What  quantities  of  silver,  gold,  and  mer- 
cury can  be  precipitated  from  their  respective  solutions  by  one 
gram  of  copper  ? 


CHAPTER  XII. 

ALUMINIUM,  TIN,  LEAD,  BISMUTH. 
ALUMINIUM.— Al. 

(1)  By  what   methods   is  this   metal  obtained  on  a  large 
scale  ?    What  are  its  properties  ?    Try  the  action  of  the  follow- 
ing  reagents  upon  aluminium  :   hydrochloric  acid,  nitric  acid, 
and  sodium  hydroxide  solution.     Write  the  reactions. 

Salts. 

(2)  Sulphate  of  Aluminium  and  Potassium. — KA1(SO4)2  -f- 
i2H,O. 


70  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

Prepare  saturated  solutions  of  aluminium  sulphate  and 
potassium  sulphate ;  mix  these  so  that  the  resulting  liquid 
contains  the  two  sulphates  approximately  in  the  proportion  of 
their  molecular  weights.  The  double  sulphate  crystallizes  on 
standing.  Why  ?  Recrystallize  it  from  water.  What  is  the 
form  of  the  crystals  ? 

What  is  an  alum  ?     (See  Richter,  p.  355.) 

Reactions. 

(3)  Use  alum.  i.  Heat  a  little  of  the  salt  on  a  platinum 
wire  in  the  oxidizing  flame,  moisten  with  cobalt  nitrate,  and 
heat  again.  A  blue  mass  (?)  is  the  product.  2.  To  an 
aqueous  solution  add  ammonia  (?).  3.  Add  ammonium  sul- 
phide to  another  portion  of  the  solution.  What  do  you 
observe  ?  4.  To  the  diluted  solution  add  sodium  hydroxide, 
drop  by  drop.  Note  the  successive  changes  (?). 

TIN.— Sn. 

(1)  Examine  a  bar  of  this  metal,     i.  Note  the  sound  it  emits 
on  bending  (?).     2.   Etch  a  smooth  surface  with  hydrochloric 
acid  (?).     3.  Try  the  solution  of  tin  in  hot  hydrochloric  acid. 
4.  What  action  have  moderately  dilute,  and  concentrated, 
nitric  acid  upon  it?     Write  the  reactions. 

(2)  Determine  the  Specific  Heat  of  Tin. 

A  thin  glass  beaker  of  about  200  cc.  capacity  is  carefully 
covered  on  the  outside  with  a  moderately  thin  layer  of  cotton 
wool.  This  may  be  called  the  calorimeter.  Pour  100  cc.  of 
distilled  water  into  the  beaker.  Suspend  the  thermometer  in 
the  water.  Place  25  grams  of  granulated  tin  into  a  test- 
tube,  close  the  mouth  o'f  the  latter  with  a  plug  of  cotton. 
Introduce  the  test-tube  with  its  contents  into  a  beaker  glass 
containing  boiling  water.  A  stout  copper  wire  will  serve  as  a 
handle.  After  10  or  15  minutes  the  tin  will  have  acquired  the 
temperature  of  the  boiling  water — 100°.  The  tube  is  then 


TIN.  71 

rapidly  removed  from  the  latter  and  its  outer  surface  freed 
from  moisture  by  quickly  passing  a  towel  over  it.  Remove 
the  cotton  from  the  mouth,  and  transfer  the  tin  to  the  calori- 
meter. While  the  metal  is  being  introduced  raise  the  ther- 
mometer from  the  water,  and  replace  it  as  soon  as  all  the 
metal  has  been  added  ;  stir  the  liquid  well  and  observe,  as 
accurately  as  possible,  the  highest  point  reached  by  the  mer- 
cury column.  Approximate  results  can  be  obtained  from 
these  data.  Calculate  as  follows  :  — 

Let  y  —  temperature  of  water  before  introducing  the 
"    z  =  «  "       "     after  " 

"  w  =  weight  of  the  water. 
«  v  —  "  of  the  metal. 
"  x  —  sp.  heat  —  then 


tin. 


x==  IPO 


25  (ioo-z) 

(Study  Richter  pp.  260-263.)  Would'  the  specific  heat 
found  for  tin,  when  divided  into  the  constant  6.4  give  the 
same  value  as  that  found  in  experiment  (3)  for  the  equivalent 
of  tin?  Explain.  How  many  series  of  tin  compounds  are 
there  ? 

(3)  Determine  the  Equivalent  Weight  of  Tin. 

Place  about  two  grams  of  tin  in  a  porcelain  crucible  that 
has  been  previously  weighed.  Cover  the  metal  with  5-10  cc. 
of  concentrated  nitric  acid.  Then  carefully  apply  heat  by 
means  of  an  iron  plate.  The  tin  is  dissolved,  while  fumes  of 
nitrogen  dioxide  are  set  free.  When  the  acid  has  been 
entirely  expelled,  heat  the  crucible  with  the  white  stannic 
oxide  over  a  Bunsen  burner;  allow  to  cool  and  weigh. 

Let  w  =  weight  of  crucible  and  tin  dioxide. 
"     v  =       "  "          "     metallic  tin. 

(«  y      .  «  «  « 

Then  w  -  v  =  weight  of  oxygen, 
and  v  -  y  =       "       "   tin. 

w-v 


72  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

Salts. 

(4)  Stannous  Chloride. — SnCl2. 

Dissolve  10  grams  of  granulated  tin  in  warm  concentrated 
hydrochloric  acid  with  the  addition  of  a  few  drops  of  platinic 
chloride  (?).  Put  the  solution  into  a  well-stoppered  bottle. 

Reactions. 

(5)  Stannous  Compounds. — Use  the  chloride  solution. 

i.  Conduct  hydrogen  sulphide  through  a  portion  of  the 
diluted  liquid.  A  brown  precipitate  (?)  is  thrown  down.  Is 
it  soluble  in  yellow  ammonium  sulphide?  What  does  hydro- 
chloric acid  precipitate  from  the  sulphide  solution  ?  2.  What 
is  the  action  of  mercuric  chloride  upon  Stannous  chloride 
(see  p.  64)  ? 

(6)  Stannic  Compounds. — Add  a  few  drops  of  bromine  to  a 
portion  of  the  Stannous  chloride  solution,  and  boil  (?).     Use 
the  diluted  liquid  for  the  tests. 

1.  Pass  hydrogen  sulphide  into  a  portion  of  the  solution. 
What  is  the  color  of  the  precipitate?     Is  it  soluble  in  hydro- 
chloric acid  ?  in  ammonium  sulphide  ? 

2.  Add  copper-turnings,  boil,  decant  the  liquid,  and  add 
mercuric  chloride.     What  happens?     Explain. 

LEAD.— Pb. 

(i)  How  can  this  metal  be  obtained  from  the  oxide?  By 
what  physical  properties  can  it  be  distinguished  from  other 
metals?  Is  it  soluble  in  the  mineral  acids?  (2)  In  a  solu- 
tion of  five  grams  of  lead  acetate  in  about  50  cc.  of  water, 
suspend  a  strip  of  metallic  zinc  and  let  stand  for  a  few  days  (?). 

Salts. 

(3)  Dissolve  five  grams  of  granulated  lead  (test-lead)  by 
warming  with  dilute  nitric  acid.  Concentrate  by  evaporation 
and  allow  to  crystallize. 


BISMUTH.  73 

Reactions. 

(4)  i.  Before  the  blowpipe,  on  charcoal,  lead  compounds 
are  reduced  to  metallic  beads,  which  are  sectile  with  the 
knife.  ...2.  Add  hydrochloric  acid  to  a  solution  of  the  nitrate. 
Boil  the  precipitate  with  water  (?).  What  takes  place  on 
cooling?  3.  To  another  portion  add  dilute  sulphuric  acid  (?). 
4.  Pass  hydrogen  sulphide  into  a  third  portion  (?). 

BISMUTH.— Bi. 
Reactions. 

(i)  i.  Mix  a  little  of  the  oxide  or  nitrate  of  bismuth  with 
sodium  carbonate  and  heat  in  the  reducing  flame  on  char- 
coal. Does  the  resulting  metallic  globule  resemble  lead  ?  Is 
it  sectile?  2.  Pass  hydrogen  sulphide  into  a  solution  of  the 
chloride  or  nitrate  in  presence  of  hydrochloric  acid  (?).  3. 
Add  a  large  volume  of  water  to  a  bismuth  solution.  What 
occurs?  What  reactions  distinguish  aluminium,  tin,  lead,  and 
bismuth  from  each  other  and  from  the  metals"  previously 
studied  ? 

Problems. — i.   What  is  the  molecular  formula  of  a  mineral 

containing 

Si02  =  43.08 

A1208  =  36-82 

CaO  =  20.10 


2.  A  compound  of  tin  and  chlorine  yielded  on  analysis 
29.42  parts  of  tin  and  35.40  parts  of  chlorine;  its  vapor 
density  was  ascertained  to  be  132.85.  What  is  the  atomic 
weight  of  tin  ?  3.  Deduce  the  formula  of  Cosalite  from  the 
following  analysis: — 

S  =  15.27 
Bi  =  41.76 
Pb  =  40.32 


1 00.00 
10 


74  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

CHAPTER  XIII. 

CHROMIUM,  MANGANESE,  IRON,  NICKEL,  COBALT. 
CHROMIUM.— Cr. 

CHROMIUM  AND  OXYGEN. 

(1)  Chromic  Oxide. — Cr2O3. 

i.  Preparation. — Mix  intimately  20  grams  of  potassium  di- 
chromate  and  four  grams  of  sulphur.  Heat  the  mixture  in  a 
porcelain  crucible  over  the  blast  lamp  for  about  20  minutes. 
Cool,  extract  the  residue  with  boiling  water  and  dry  it  at  a 
gentle  heat.  What  is  its  color ;  is  it  soluble  in  dilute  hydro- 
chloric acid  ?  2.  Fuse  a  portion  of  it  with  six  times  its  weight 
of  sodium  bisulphate  in  a  platinum  crucible.  What  takes 
place  ?  3.  Repeat  this  experiment  with  some  finely  powdered 
chromite.  (?) 

Salts. 

(2)  Chromic  Chloride.— CrCl3. 

Prepare  the  Anhydrous  Salt. — Intimately  mix  10  grams  of 
chromic  oxide,  prepared  as  described,  and  three  grams  of 
powdered  charcoal,  and  convert  this  into  a  dough  with  a  little 
starch  paste.  Form  the  product  into  balls  of  the  size  of  a  pea ; 
dry,  and  then  ignite  these  (covered  with  charcoal  powder)  in 
a  Hessian  crucible,  provided  with  well-fitting  lid.  Place  the 
residue  into  a  tube  of  hard  glass,  and  heat  it  in  a  current  of 
carbon  dioxide  to  expel  every  trace  of  moisture.  With  the  aid 
of  a  blast  lamp  increase  the  temperature  and  replace  the  car- 
bon dioxide  by  a  current  of  chlorine.  The  excess  of  chlorine 
should  be  absorbed  by  conducting  it  into  a  bottle  filled  with 
caustic  soda.  (?)  The  resulting  chromium  trichloride  sublimes 
to  the  cooler  portions  of  the  tube.  Describe  its  appearance. 
Is  it  soluble  in  water  ? 


CHROMIUM.  75 

What  other  chlorides  are  prepared  in  a  similar  way  ?    Write 
the  equation,  expressing  the  reaction. 

(3)  Chrome  Alum.—  Cr2(SO4)3-K2SO4  +  24  H2O. 
Dissolve  10  grams  of  potassium  bichromate  in  a  little  water ; 

acidify  with  sulphuric  acid,  pass  sulphur  dioxide  into  the 
liquid  until  the  latter  is  saturated  with  the  gas.  Allow  to 
stand ;  the  double  salt  crystallizes.  What  is  its  crystalline 
form?  Dissolve  some  of  it  in  cold  water  and  note  the  color 
of  the  solution  ;  now  warm  it.  What  takes  place  (see  Richter, 
p.  382)? 

(4)  i.   Examine  crystals  of  potassium  dichromate.     How  is 
it  obtained  ?     2.  Dissolve  10  grams  of  this  salt  in  water,  and 
from  a  burette  carefully  add  a  caustic  soda  solution  until  the 
color  is  changed  to  yellow  (?).     What  crystallizes  from  the 
solution  on  evaporation  ?    How  can  you  reconvert  the  product 
into  the  dichromate? 

Reactions. 

(5)  i.   Dissolve  a  minute  quantity  of  a  chromium   com- 
pound in  a  borax  bead.     Heat  in  the  oxidizing  and  in  the 
reducing  flame.     Results?     2.  Heat  a  little  of  the  compound 
with  potassium  nitrate  on  a  platinum  foil  (?). 

(6)  Chromic  Compounds. — Use  chrome  alum  for  the  tests. 
i.  Add  caustic  soda,  drop  by  drop,  to  a  little  of  the  solution.  (?) 
Continue  the  addition  of  the  reagent  till  the  precipitate  is 
redissolved.     What  takes  place  on  boiling  the  solution?     2. 
What  is  the  action  of  ammonia  on  the  solution  of  the  chro- 
mium salt?     3.  Add  an  excess  of  potassium  hydrate  to  the 
chromium  solution  until  the  precipitate  is  redissolved.     Now 
add  5-10  cc.    of  bromine   water  and  boil.      What  occurs? 
Explain. 

(7)  Chromates. — Use   a   solution    of  potassium    chromate. 
i.  Add  lead  acetate  solution.     Note  the  color  of  the  precipi- 
tate.    Is   it   soluble   in    acetic   acid?     2.  Substitute    barium 
chloride  for  the  lead  salt  in  the  preceding  experiment  (?). 


76  EXPERIMENTS   IN    GENERAL   CHEMISTRY. 

3.  Acidify  the  chromate  solution  with  sulphuric  acid  and  add 
hydrogen  peroxide  to  the  liquid.  What  happens?  4.  To 
some  of  the  chromate  solution  add  a  few  drops  of  hydrochloric 
acid  and  about  one  cc.  of  alcohol.  What  occurs  when  the 
mixture  is  heated  to  boiling? 

MANGANESE.— Mn. 
MANGANESE    AND    OXYGEN. 

(1)  In  what  proportions  do  these  two  elements  unite  with 
each  other?     Enumerate  the  oxides  which  occur  in  nature. 
What  is  formed  when  the  oxides  of  manganese  are  heated  in 
hydrogen  ?     When  they  are  ignited  in  the  air  ? 

Salts. 

(2)  Manganous  Chloride. — MnCl2  -f-  4H2O. 

Evaporate  in  a  porcelain  dish  the  solution  obtained  in  the 
preparation  of  chlorine  from  manganese  dioxide  and  hydro- 
chloric acid.  Heat  the  dry  residue  over  a  small  flame  for 
some  time.  Add  much  water  and  boil.  Filter,  and  to  y1^  of 
the  filtrate  add  a  solution  of  sodium  carbonate  in  excess. 
Allow  the  precipitate  (?)  to  settle,  draw  off  the  supernatant 
liquid  with  a  siphon,  and  wash  the  remaining  precipitate 
several  times  with  water  by  decantation.  Add  the  precipitate 
then  to  the  principal  solution,  and  digest  at  a  gentle  heat 
until  a  small  filtered  sample  mixed  with  ammonium  sulphide 
gives  a  flesh-colored  precipitate  which  is  completely  dissolved 
by  dilute  acetic  acid.  Now  filter  and  evaporate  to  crystalli- 
zation. 

.  (3)  Potassium  Manganate—}Z..2MnQ^  and  Potassium  Per- 
manganate— K2Mn.2O8. 

In  a  porcelain  crucible  fuse  a  mixture  of  five  grams  caustic 
potash  and  2.5  grams  potassium  chlorate;  gradually  add  five 
grams  finely  powdered  manganese  dioxide.  Maintain  a 
moderate  red  heat  for  15  minutes.  Dissolve  the  dark-green 


IRON.  77 

residue  in  a  little  water.  Observe  the  color  of  the  solution. 
What  does  it  contain?  Then  dilute  with  much  water  and 
conduct  carbon  dioxide  into  the  liquid.  Is  there  any  change  ? 
If  so,  write  the  equation  expressing  it. 

Potassium  permanganate  as  well  as  potassium  manganate  are 
powerful  oxidizing  agents.  Warm  a  little  of  the  alkaline  po- 
tassium manganate  solution  with  a  few  drops  of  alcohol  (?). 
To  a  little  of  the  permanganate  solution,  acidified  with  sul- 
phuric acid,  add  sulphurous  acid  (?).  Treat  the  acidified 
solution  also  with  solutions  of  ferrous  sulphate  and  oxalic 
acid  (?). 

Reactions. 

(4)  i.  What  color  do  manganese  compounds  impart  to  a 
borax  bead  in  the  oxidizing  flame  ?  What  is  the  effect  of  the 
reducing  flame  ?  2.  Heat  a  little  of  a  manganese  compound 
with  sodium  carbonate  and  potassium  nitrate  on  a  platinum 
foil.  What  does  the  resulting  mass  contain?  3.  To  a  little 
of  the  solution  of  the  chloride  in  water  add  ammonium  sul- 
phide. What  is  the  color  of  the  precipitate?  Test  its  solu- 
bility in  acids  (including  acetic  acid).  4.  Add  caustic  soda 
to  another  portion  of  the  chloride  solution.  Is  the  precipitate 
soluble  in  an  excess  of  the  reagent  ?  Is  its  color  affected  by 
exposure  to  the  air?  Explain. 

IRON.— Fe. 

(i)  Preparation. — Into  a  tube  of  Bohemian  glass  place  a 
porcelain  boat  filled  with  the  finely  powdered  oxide.  Pass  a 
current  of  dry  hydrogen  through  the  tube,  and  when  all  the 
air  is  expelled  (how  could  you  test  it  ?),  apply  heat  to  that 
part  of  the  tube  which  contains  the  boat.  What  is  formed  in 
the  anterior  portion  of  the  tube  !  After  a  red  heat  has  been 
maintained  for  10  minutes  allow  the  boat  to  cool  in  hydrogen 
and  examine  its  contents.  Are  they  attracted  by  the  magnet  ? 
Expose  the  product  to  the  air  (?). 


7$  EXPERIMENTS   IN    GENERAL   CHEMISTRY. 

How  is  iron  obtained  from  its  ores  on  a  large  scale  ?  What 
are  its  properties  ?  (see  Richter,  pp.  396,  400).  Distinguish 
between  cast-iron,  steel,  and  wrought-iron. 


(2)  Ferrous  Sulphate.—  FeSO4  -f  7H20- 

To  25  grams  of  iron  in  the  fprm  of  nails  or  wire,  free  from 
rust,  contained  in  a  flask,  add  200  cc.  of  dilute  (i  :  4)  sul- 
phuric acid.  When  the  evolution  of  the  gas  (?  Note  its 
odor  !)  is  no  longer  violent,  warm,  and  finally  boil  until  the 
liberation  of  gas  ceases.  A  sample  of  the  solution  poured 
into  a  test  tube  should,  on  cooling,  give  a  copious  separation 
of  crystals.  Filter  into  a  casserole  containing  two  to  three  cc. 
of  cone,  sulphuric  acid,  and  let  stand  for  eight  hours.  Collect 
the  crystallized  product  in  a  funnel  the  stem  of  which  is 
closed  with  a  loose  plug  of  glass  wool,*  allow  the  mother 
liquor  to  drain  off,  wash  with  very  little  cold  water  (?), 
and  dry  between  sheets  of  filter  paper.  Examine  the  pro- 
duct carefully.  Note  its  color,  taste,  solubility  in  water,  and 
crystal  form.  What  other  salts  of  analogous  composition  are 
isomorphous  with  it? 

What  is  observed  when  some  of  the  salt  is  heated,  first 
moderately,  then  strongly,  in  a  tube  of  hard  glass? 

Expose  the  aqueous  solution  of  the  salt  to  the  air  for  several 
hours  (?). 

(3)  Ferrous     Ammonium     Sulphate.  —  Fe(NH4)2(SO4)2  -f- 
6H2O. 

In  100  cc.  of  dilute  sulphuric  acid  dissolve  clean  iron  wire 
till  no  more  hydrogen  is  given  off;  neutralize  a  like  quantity  of 
the  acid  exactly  with  ammonia  water,  and  add  to  it  a  few  drops 
of  dilute  sulphuric  acid.  Filter  the  iron  solution  into  that  of 


*  It  is  better  to  use  a  perforated  platinum  cone,  and  to  remove  the  ad- 
hering solution  with  the  aid  of  a  filter  pump. 


IRON.  79 

the  ammonium  salt.  Let  the  salt  crystallize,  drain 'it  on  a 
funnel  provided  with  a  perforated  platinum  cone,  wash  and 
dry  as  described  under  (2).  Preserve  in  a  well-stoppered 
bottle.  What  metals  can  replace  the  iron  in  this  salt  without 
altering  its  crystalline  form  ? 

(4)  Ferric  Ammonium  Sulphate.—  Fe2(SO4)3.  (NH4)2SO4  -f 
24H20. 

Place  20  grams  of  crystallized  ferrous  sulphate  into  a  porce- 
lain dish  together  with  a  few  cc.  of  water  and  3.5  grams  of  oil 
of  vitriol.  Warm  on  an  asbestos  plate,  adding  nitric  acid, 
drop  by  drop,  until  no  further  change  of  color  (?)  is  observed. 
Evaporate  the  excess  of  nitric  acid,  dissolve  the  residue  in  hot 
water  and  add  3.5  grams  of  ammonium  sulphate;  filter,  and 
set  the  solution  aside  for  crystallization.  Separate  the  crystals 
from  the  mother  liquor,  and  wash  and  dry  jthem  as  under  (2). 
To  what  class  of  substances  does  this  salt  belong  ?  Why  ? 

Reactions. 

(5)  In  a  borax  bead  dissolve  a  small  quantity  of  an  iron  com- 
pound, and  treat  it  successively  in  the  oxidizing  and  reducing 
flames.     What  changes  do  you  observe  ? 

(6)  Ferrous   Compounds. — Use  a  freshly  prepared  solution 
of  ferrous  sulphate  for  the  following  tests :   i.  To  a  few  drops 
of  it,  diluted  with  water,  add  ammonia.     Note  the  color  of  the 
precipitate,  and  the  changes  which  occur  on  exposure  to  the 
air  (?).      2.  Add  ammonium  sulphide  to  another  portion  (?). 
Is   the   resulting  precipitate   soluble   in   hydrochloric   acid  ? 
3.   In  a  porcelain  capsule  bring  together  a  little  of  the  ferrous 
solution   and   a  drop  of  a  potassium  ferrocyanide   solution. 
Result  ?     4.  In  a  similar  manner  test  a  drop  of  the  iron  solu- 
tion with  ferricyanide  of  potassium. 

(7)  Ferric    Compounds. — In    the   presence   of    free   acids, 
oxidizing  agents  convert  iron   compounds  from   the  ferrous 
into  the  ferric  condition,     i.  Acidify  the   ferrous  sulphate 
solution  with  sulphuric  acid,  warm,  and  add  concentrated 


80  EXPERIMENTS    IN    GENERAL   CHEMISTRY. 

nitric  acid  until  it  fails  to  produce  a  change  in  color:  the 
iron  is  then  in  the  ferric  state.  2.  Dilute  a  few  drops  of  the 
yellow  liquid  with  several  cc.  of  water  and  add  ammonia  (?). 
3.  Test  a  drop  of  the  ferric  solution  with  potassium  ferrocya- 
nide  (?).  4.  Treat  a  second  drop  with  ferricyanide  of  potas- 
sium (?).  5.  Mix  another  drop  with  a  solution  of  potassium 
sulphocyanate  (?).  6.  Conduct  hydrogen  sulphide  into  some 
of  the  ferric  sulphate  solution.  What  do  you  observe? 
Explain  the  reaction,  and  write  the  equation  expressing  it. 
7.  Place  a  piece  of  metallic  zinc  in  a  test-tube  containing  a 
solution  of  the  ferric  salt.  What  takes  place  ? 

(8)  Quantitative  Estimation  of  Iron. — Under  manganese  it 
was  observed  that  the  salt  potassium  permanganate  is  an  oxi- 
dizing agent.  To  show  how  this  salt  acts  with  iron  in  its 
lower  form  of  oxidation,  fill  a  burette  with  an  aqueous  solu- 
tion of  it ;  allow  it  to  drop  slowly  into  the  solution  of  a 
ferrous  salt  acidulated  with  sulphuric  acid.  The  pink  color 
of  the  permanganate  immediately  disappears  on  stirring  with 
a  glass  rod.  This  continues  until  the  ferrous  salt  is  completely 
oxidized  to  the  ferric  state.  A  drop  of  permanganate  added 
in  excess  will  then  impart  a  faint  pink  color  to  the  liquid. 
This  indicates  that  the  reaction  is  ended.  Write  the 

FIG.  40. 

equation. 

This  behavior  may  be  utilized  for  determining 
the  quantity  of  iron  in  a  solution.  That  this  may 
be  done,  it  is  first  necessary  to  standardize  the  per- 
manganate solution.  Proceed  as  follows  :  Dissolve 
about  two  grams  of  the  permanganate  in  1000  cc. 
of  water.  Fill  a  burette  with  this  solution.  Weigh 
out  .2  gram  of  clean  piano  wire.  Place  this  into  a  small  flask 
(Fig.  40)  provided  with  a  cork  and  valve.*  Cover  the  iron 
wire  with  dilute  sulphuric  acid.  Warm.  When  the  iron  is 

*With   a   sharp  knife  make  a  longitudinal  incision  of  about  one  cm, 
length,  in  a  rubber  tube,  and  close  one  end  by  means  of  a  glass  rod, 


COBALT    AND    NICKEL.  8 1 

completely  dissolved,  remove  the  cork,  add  cold  water  to  the 
solution,  and  slowly  admit  the  permanganate  until  the  final 
pink  coloration  appears.  Note  the  volume  of  permanganate 
required  to  produce  this  effect.  Suppose  30  cc.  had  been 
consumed,  then  : — 

30  cc.  K2Mn2O8  =  .2000    gram  metallic  iron. 
i   «         "          =  .00666     "  "  " 

This  is  then  the  standard  of  the  permanganate  in  iron  units. 

Next,  dissolve  one  gram  of  ferrous  ammonium  sulphate, 
in  100  cc.  distilled  water,  add  five  cc.  of  sulphuric  acid,  and 
then  introduce  the  permanganate  until  the  final  reaction  is 
observed.  Calculate  the  percentage  of  iron  in  this  salt  and 
compare  the  experimental  result  with  the  theoretical  value. 

How  much  oxygen  will  each  molecule  of  permanganate 
give  up  in  oxidizing  ?  How  many  molecules  of  ferrous  oxide 
can  be  changed  to  ferric  oxide  by  a  molecule  of  potassium 
permanganate. 

COBALT.— Co,  AND   NICKEL.— Ni. 

Reactions. 

i.  Dissolve  a  minute  quantity  of  a  cobalt  compound  in  a 
borax  bead.  Heat  first  in  the  oxidizing,  then  in  the  reducing 
flame  (?).  2.  What  is  the  behavior  of  nickel  compounds 
under  like  conditions?  3.  Add  caustic  alkali  to  a  solution  of 
cobalt  nitrate,  warm  the  mixture  (?).  4.  What  action  have 
caustic  alkalies  on  solutions  of  nickel  salts?  5.  To  the  co- 
balt solution  cautiously  add  ammonia.  After  a  precipitate  (?) 
has  formed,  add  more  of  the  reagent.  What  takes  place? 
Expose  the  resulting  solution  to  the  air  in  a  shallow  dish  (?). 
6.  Treat  a  nickel  solution  in  an  analogous  manner  (?)  7.  To 
the  solutions  of  cobalt  and  nickel  each  in  a  separate  test-tube, 
add  ammonium  sulphide.  Filter  and  wash  the  precipitated 
sulphides,  and  test  their  solubility  in  acids  (?). 


82  EXPERIMENTS    IN    GENERAL    CHEMISTRY. 

Note  the  colors  of  cobalt  and  nickel  salts,  in  the  hydrated 
as  well  as  in  the  anhydrous  state. 

Nickel  Carbonyl. — A  tube  of  hard  glass  is  drawn  out  to  a 
bayonet  at  one  end,  and  filled  with  nickel  oxide.  A  current 
of  nydrogen  is  conducted  through  the  tube,  while  the  tempera- 
ture is  raised  to  a  low  red  heat.  This  is  maintained  until 

moisture  ceases  to  condense,  when 

FIG.  41.  ,  •  i      j  • 

the  escaping  hydrogen  impinges 
on  a  cool  surface.  Cool  in  an 
atmosphere  of  hydrogen.  Carbon 
monoxide,  washed  with  caustic 
potash  and  sulphuric  acid,  is  now 
passed  through  the  apparatus,  and  the  issuing  gas  is  led 
through  a  tube  (Fig.  41)  surrounded  by  a  freezing  mixture 
(care  !).  What  is  the  colorless  mobile  liquid  which  condenses  ? 
This  experiment  should  be  conducted  under  a  hood  (?). 

Is  there  any  marked  difference  between  cobalt  and  nickel 
in  respect  to  their  chemical  deportment? 


Point  out  the  differences  in  the  reactions  of  chromium, 
manganese,  iron,  cobalt,  and  nickel. 

How  may  ferrous  compounds  be  distinguished  from  ferric? 
What  conditions  are  favorable  to  the  conversion  of  the  former 
into  the  latter?  The  latter  into  the  former? 

By  what  means  may  chromic  salts  be  changed  into  com- 
pounds of  chromic  acid  ?  How  may  the  reverse  change  be 
effected? 

Devise  a  method  for  separating  the  elements  treated  in  this 
chapter. 

Problems. — i.  How  much  potassium  bichromate  can  be 
obtained  theoretically  from  100  kilos  of  a  chromite  contain- 
ing 58.6  per  cent,  of  chromic  oxide?  2.  100  grams  of  a 


PLATINUM. 

pyrolusite,  which  was  found  to  contain  four  per  cent,  of  im- 
purities, will  give  what  volume  of  oxygen,  measured  at  20°  C. 
and  745  mm.,  when  strongly  ignited ?  What  is  the  weight 
of  the  residue,  assuming  that  one-half  of  the  impurities  was 
moisture,  the  other  half  quartz?  3.  How  many  grams  of 
nitric  acid  are  required  to  oxidize  12  grams  of  crystallized 
ferrous  sulphate  ?  4,  What  percentage  of  metallic  iron  is 
contained  in  a  salt,  of  which  .7  gram  are  exactly  oxidized 
by  17.8  cc.  of  permanganate  solution  (standard  :  i  cc.  =  .0056 
gram  Fe)  ? 


CHAPTER   XIV. 

Name  the  metals  constituting  the  platinum  group. 

PLATINUM. 

(1)  Examine  the  metal  in  the  form  of  foil  or  wire.     Note 
its  color  and  lustre.     Determine  its  specific  gravity.     Is  it 
fusible  in  the  flame  of  the  Bunsen  burner  or  the  blast  lamp  ? 

(2)  What  are  its  chemical  properties?     Place  a  small  piece 
of  the  metal  into  a  test-tube  and  heat  it  with  concentrated 
hydrochloric  acid.     Any  action?     Treat  another  piece  with 
nitric  acid.     Result?     Combine   the  contents  of  both  test- 
tubes  and  warm.     What  takes  place? 

Platinic  Chloride — PtCl4. — Boil  platinum  scrap  with  hydro- 
chloric acid.  Decant  the  liquid,  and  dissolve  the  remaining 
metal  in  nitro-hydrochloric  acid.  Concentrate  the  resulting 
solution  by  evaporation  on  the  water  bath,  and  add  a  strong 
solution  of  ammonium  chloride.  Filter  off  the  precipitated 
platinic  ammonium  chloride,  and  after  careful  drying,  ignite 
it  in  a  large  porcelain  crucible.  Extract  the  residue  01 
spongy  platinum  with  boiling  hydrochloric  acid,  then  djs- 


84  EXPERIMENTS   IN    GENERAL   CHEMISTRY. 

solve  it  in  aqua  regia,  and  evaporate  to  dry  ness  on  the  water 
bath.  Moisten  the  residue  with  hydrochloric  acid  and  again 
evaporate.  Dissolve  the  product  in  distilled  water. 

Reactions. 

Use  platinic  chloride  for  the  tests,  i.  Add  hydrogen  sul- 
phide water  and  apply  a  gentle  heat.  2.  Add  a  little  grape 
sugar  and  caustic  soda  to  a  second  portion.  Warm.  See 
under  potassium  and  sodium  how  solutions  of  this  metal 
behave  with  alkaline  chlorides,  etc. 


APPENDIX. 


TABLE   OF   METRIC   WEIGHTS  AND  MEASURES. 


MEASURES  OF  LENGTH. 

i  metre  —  10  decimetres  =  100  centimetres  =  1000  millimetres, 
i  metre  =  1.09363  yards  =  3.2809  feet          =  39.3709  inches. 

MEASURES  OF  CAPACITY. 

i  cubic  metre  =  1000  litres  =  1,000,000  cubic  centimetres  1,000,000,000 
cubic  millimetres. 

i  litre  =  61.02705  cubic  inches  =  .035317  cubic  foot  =  1.76077 
pints  =  .22097  gallon. 

MEASURES  OF  WEIGHT. 
I  gram          =  weight  of  i  cc.  of  water  at  4°  C. 

i  Kilogram  =  1000  grams  =  100.000  centigrams  =  1,000,000  milli- 
grams. 

I  Kilogram  =  2.20462  Ibs.  =  35.2739  ounces  =  15432.35  grains. 

TABLE  OF  ATOMIC  WEIGHTS  OF  ELEMENTS. 


Aluminium,  .    . 

.  Al 

.    .       27.0 

Chromium,    . 

.    .  Cr      .    . 

52.5 

Antimony,     .    . 

.  Sb 

.     .       120.0 

Cobalt,  .    . 

.    .  Co      .    . 

59-o 

Arsenic,    .    .    . 

.  As 

.     .          75.0 

Copper,     .    . 

.    .  Cu     .    . 

63.3 

Barium,     .    .    . 

.  Ba 

.     v       137.0 

Fluorine,  .    . 

.    .  Fl      .    . 

19.0 

Bismuth,   ... 

.  Bi 

.     .       2080 

Gold,     .    .  -. 

.    .  Au     .    . 

197.0 

Boron,  .... 

.  B 

.     .          II.O 

Hydrogen,    . 

.    .  H       .    . 

I.O 

Bromine,   .    .    . 

.  Br 

8O.O 

Iodine, 

I        .    . 

127.0 

Cadmium, 

.  Cd 

.     .       1  1  2.0 

Iron,      .    .    . 

.    .  Fe      .    . 

^/  *w 
56.0 

Calcium,   .    .    . 

.Ca 

.     .          4O.O 

Lead,    .    .    . 

.    .  Pb      .    . 

207.0 

Carbon,     .    .    . 

.  C 

.     .          12.0 

Magnesium, 

.    .  Mg    .    . 

24.0 

Chlorine,   .    .    . 

.  Cl 

•   •      35-5 

Manganese,  . 

.    .  Mn    .    . 

550 

86 


APPENDIX. 


TABLE  OF  ATOMIC  WEIGHTS  OF  ELEMENTS.— Continued. 


Mercury,   .    . 

•    .  Hg    .    . 

2OO.O 

Silicon, 

.    .  Si 

.    .        28.0 

Molybdenum, 

.    .  Mo     .    . 

96.0 

Silver,  .    . 

•    .Ag 

.    .      108.0 

Nickel,      .    . 

.    .  Ni      .    . 

cq.o 

Sodium, 

Na 

o 

Nitrogen,  .    . 

.    .  N       .    . 

14.0 

Strontium, 

.    .  Sr 

.    .        87.5 

Oxygen,    .    . 

.    .  O       .    . 

16.0 

Sulphur, 

.  .  s- 

Phosphorus, 

.    .  P 

Tin,  .    .    . 

.    .  Sn 

118  o 

Platinum, 

.    .  Pt      .    . 

195.0 

Zinc,      .    . 

.    .  Zn 

.    .       65.0 

Potassium,     . 

.    .  K       .    . 

390 

TENSION  OF  AQUEOUS  VAPOR  IN  MILLIMETRES  (Regnault}. 


TEMP. 

TENSION. 

TEMP. 

TENSION. 

TEMP. 

TENSION. 

0° 

4.6 

11° 

9.8 

21° 

18.5 

I 

4-9 

12 

10.4 

22 

19.7 

2 

5-3 

13 

II.  I 

23 

20.9 

3 

5-7 

14 

II.9 

24 

22.2 

4 

6.1 

15 

12.7 

25 

23-6 

5 

6.5 

16 

'3-5 

26 

25.0 

6 

7.0 

17 

14.4 

27 

26.5 

7 

7-5 

18 

15-4 

28 

28.1 

8 

8.0 

19 

16.3 

29 

29.8 

9 

8.5 

20 

17.4 

30 

31.6 

10 

9.1 

THE   SPECIFIC  GRAVITY  AND  THE  WEIGHT   OF  A  LITRE 
OF  GASES. 


SPECIFIC  GRAVITY  (Regnaulf). 

AT  0°  AND  760  MM. 

REFERRED    TO 
WATER  AT  4°. 

REFERRED   TO    AIR 
UNDER  LIKE  TEM- 
PERATURE AND 
PRESSURE. 

ONE  LITRE  IN  ITS 
NORMAL  CON- 
DITION, IN  GRAMS. 

Air,     

0.0012928 

I.OOOOO 

1.2932 

Oxygen  

0.0014293                    1.10563 

1.4300 

Nitrogen,   .... 

0.0012557                    0.97137 

1.2562 

Hydrogen,     .    f    . 

0.00008954                 0.06926 

0.0896 

Carbon  dioxide,     . 

0.001977 

1.529 

1.9663 

OF  THE 


Catalogue  No.  4.  December,  1895. 

A   CATALOGUE 

OF 

Chemical  Technological 

AND  SCIENTIFIC  BOOKS 

INCLUDING 

BOOKS    ON    MICROSCOPY,  WATER   ANALYSIS, 
MILK   ANALYSIS,    HYGIENE,   TOXI- 
COLOGY, ETC. 

P.  BLAK1STON,  SON  &  CO., 

PUBLISHERS  AND  BOOKSELLERS  OF  SCIENTIFIC  AND  MEDICAL  BOOKS, 

1012  WALNUT  STREET,   PHILADELPHIA.- 


INDEX    OF    SUBJECTS. 

PAGE 

GROVE  AND  THORP,  CHEMICAL  TECHNOLOGY, 2 

RICHTER'S  CHEMISTRIES,  ORGANIC  AND  INORGANIC, 3 

CHEMISTRY  AND  CHEMICAL  ANALYSIS, 4 

TOXICOLOGY,  MEDICAL  JURISPRUDENCE, 8 

TECHNOLOGICAL  AND  MANUFACTURERS'  BOOKS, 9 

WATER  AND  MILK  ANALYSIS, 10 

MICROSCOPY,    ....       n 

GOULD'S  DICTIONARY  OF  MEDICINE  (CHEMISTRY,  BIOLOGY,  ETC.),     .   .   .  n 

HYGIENE  AND  SANITARY  SCIENCE, 12 


The   prices   given   in  this   Catalogue  are  absolutely  net.     No 
discount  whatever  can  be  allowed  retail  purchasers. 


P.  Blakiston,  Son  &  Co.'s  publications  may  be  had  through  Booksellers 
in  all  the  principal  cities  of  the  United  States  and  Canada.  Any  book  will  be 
sent,  postpaid,  upon  receipt  of  price,  or  will  be  forwarded  by  express,  C.  O.  D., 
upon  receiving  a  remittance  of  25  per  cent,  of  the  amount  ordered,  to  cover 
express  charges.  Money  should  be  remitted  by  postal  note,  money  order,  regis- 
tered letter,  or  bank  draft. 

Complete  catalogues  of  Books  on  Medicine,  Dentistry,  Hygiene, 
Nursing,  and  Pharmacy  will  be  sent  free  upon  application. 


IMPORTANT  ANNOUNCEMENT. 

TO   CHEMISTS,   MANUFACTURERS,  AND   ENGINEERS. 

CHEMICAL  TECHNOLOGY; 

OR,  CHEMISTRY    IN    ITS   APPLICATION    TO  ARTS 
AND   MANUFACTURES. 

EDITED   BY 

CHARLES  EDWARD  GROVES,  F.R.C.,  AND  WILLIAM  THORP,  B.Sc. 


VOL.  I.     FUEL  AND   ITS  APPLICATIONS.     By  E.  J. 

MILLS,  D.  Sc.,  F.R.S.,  and  F.  J.  ROWAN,  C.E.,  assisted  by  others, 
including  MR.  F.  P.  DEWEY,  of  the  Smithsonian  Institute, Wash- 
ington, D.  C.  7  Plates  and  607  other  Illustrations.  Royal 
Octavo,  Pages  xx  +  802. 

Handsome  Cloth,  $5.00;  Half  Morocco,  $6.50 

VOL.  II.  LIGHTING.  Fats  and  Oils,  Stearine  Industry,  Candle 
Manufacture,  Petroleum,  Lamps,  Miners'  Safety  Lamps,  etc.  By 
J.  MCARTHUR,  L.  FIELD,  F.  A.  FIELD,  BOVERTON  REDWOOD, 
and  D.  A.  Louis.  358  Illustrations.  Royal  Octavo,  Pages  xvi  -)- 
398.  Handsome  Cloth,  $4.00;  Half  Morocco,  $5.50 

VOL.  III.     LIGHTING— Continued.  In  Press. 


It  has  been  many  years  since  any  complete  work  on  chemistry,  as  applied  to 
the  arts  and  manufactures,  has  been  published.  The  editors  of  this  work  have 
endeavored  to  collect,  therefore,  all  the  practical  information  on  the  various  subjects 
to  be  treated  of,  from  the  great  mass  of  periodical  and  miscellaneous  literature, 
and  put  it  in  a  shape  for  easy  reference  and  use.  The  work  will  be  divided  into 
sections,  of  which  the  most  important  are  — 

FUEL  AND  ITS  APPLICATIONS.        TEXTILE  FABRICS. 
LIGHTING.  LEATHER,  PAPER,  ETC. 

ACIDS  AND  ALKALIES.  COLORING  MATTER  AND  DYES. 

GLASS  AND  POTTERY.  OILS  AND  VARNISHES. 

METALLURGY.  BREWING  AND  DISTILLING. 

SUGAR,  STARCH,  FLOUR,  ETC. 


Special   circular,  with   List  of  Contents  and  reviews  from  prominent 
papers,  sent  free  upon  application.     See  also  page  9  of  this  catalogue. 


RICHTER'S  CHEMISTRIES. 

AUTHORIZED   TRANSLATIONS. 

BY  EDGAR  F.  SMITH,  F.C.S.,  M.A.,  PH.D., 

Professor  of  Chemistry  in  the  University  of  Pennsylvania;   Member  of  the  Chemical 

Societies  of  Berlin  and  Paris  ;  of  the  Academy  of  Natural  Sciences,  of 

Philadelphia;  American  Philosophical  Society ;  Society 

Chemical  Indust.,  England,  etc.,  etc. 


INORGANIC  CHEMISTRY.  Fourth  American,  from  the 
Sixth  German  Edition ;  thoroughly  revised  and  in  many  parts  re- 
written. With  89  Illustrations  and  Colored  Plate  of  Spectra. 
i2mo.  Cloth,  $1.75 

From  Prof.  B.  Silliman,  Yale  College,  New  Haven,  Conn.:  "  It  is  decidedly  a  good 
book,  and  in  some  respects  the  best  manual  we  have." 

From  Prof.  Sam1  IS.  Green,  Swarthmore  College,  Penna.:  "  I  am  of  the  opinion  that 
it  is  the  best  text-book  of  the  kind  I  have  seen.  I  shall  recommend  it  to  my  classes." 

From  Prof.  A.  A.  Bennett,  Chicago  University :  "  I  am  satisfied  this  work  is  the  best 
that  I  have  yet  seen,  and  that  it  will  in  a  high  degree  fill  the  want." 

From  E.  H.  S.  Bailey,  University  of  Kansas,  Lawrence:  "  Dr.  Smith  has,  by  his  ex- 
cellent translation,  brought  into  prominence  one  of  the  best  and  most  recent  books  upon 
the  science  of  chemistry." 

From  the  Science  Record,  Boston:  "  Notwithstanding  the  multitude  of  text-books  on 
chemistry,  there  is  always  room  for  a  good  one,  and  the  present  work  will  undoubtedly 
fall  under  this  head.  Prof.  Von  Richter's  work  met  with  great  success  abroad,  owing  to 
its  unusual  merit.  In  presenting  the  subject  to  the  student,  the  author  makes  a  point  to 
bring  out  prominently  the  relations  existing  between  fact  and  theory,  too  commonly  con- 
sidered apart.  .  .  .  The  periodic  system  is  so  treated  as  to  prove  a  really  valuable  aid 
tothestudent,  and  especially  in  the  relations  of  the  metals.  .  .  .  Von  Richter's  text-book 
deserves  a  hearty  welcome  at  the  hands  of  teachers  of  chemistry  desirous  of  instructing 
in  modern  theories  and  on  a  rational  basis.  This  translation  is  neatly  printed  on  paper 
of  light  weight,  making  a  very  convenient  handbook." 

THE  CHEMISTRY  OF  THE  CARBON  COMPOUNDS, 

or  Organic  Chemistry.  Second  American,  from  Sixth  German 
Edition.  Illustrated.  121110.  Cloth,  $4-5° 

From  T.  H.  Wrampelmeier,  Ass't  Prof,  of  Organic  Chemistry  and  Pharmacy,  Uni- 
versity of  Michigan,  Ann  Arbor :  "  I  shall  recommend  it  to  my  classes  as  the  BEST  TEXT- 
BOOK on  organic  chemistry." 

FromJ.  S.  Schanck,  Princeton  College,  N.  J. :  "  I  consider  it  one  of  the  choicest  works 
on  organic  chemistry." 

From  Prof.  F.  P.  Venable,  University  of  North  Carolina,  Chapel  Hill,  N.  C. :  "The 
method  of  dividing  and  grouping  is  a  great  aid  to  the  memory  and  to  an  intelligent  con- 
ception of  the  subject." 

From  Sam1 1  T.  Sadder,  Prof,  of  General  and  Organic  Chemistry,  University  of  Penn- 
sylvania, and  Prof,  of  Chemistry,  Philadelphia  College  of  Pharmacy :  "It  presents  in  a 
concise  form  the  most  modern  views  of  the  theory,  and  gives,  moreover,  many  very  prac- 
tical methods.  .  .  .  The  freshness  of  its  information  may  be  noted.  .  .  .  I  consider 
it  compares  favorably  with  any  book  upon  this  subject  in  the  English  language." 

Prof.  Richter's  methods  of  arrangement  and  teaching  have  proved  their  superi- 
ority by  the  large  sale  of  his  books  throughout  Europe,  translations  having  been 
made  in  Russia,  Holland,  and  Italy.  The  success  attending  the  publication  in  this 
country  could  only  have  been  attained  for  good  books  that  have  been  found  useful, 
practical,  and  thoroughly  up  to  the  times.  Almost  every  teacher  who  has  examined 
them  has,  without  hesitation,  given  a  testimonial  of  their  value,  and  in  the  large 
number  of  schools  and  colleges  in  which  they  have  been  adopted  as  text-books 
they  have  stood  the  test  of  time  and  use. 

gig^  RICHTER'S  CHEMISTRIES  are  recommended  at  many 
prominent  Schools  and  Colleges.  Descriptive  Circulars  upon  application. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 

ALLEN.     Commercial  Organic  Analysis.     A  Treatise  on 

the  Modes  of  Assaying  the  Various  Organic  Chemicals  and  Products 

employed  in  the  Arts,  Manufactures,  Medicine,  etc.,  with  Concise 

Methods  for  the  Detection  of  Impurities,  Adulterations,  etc.    Second 

Edition.     Revised  and  Enlarged.     By  ALFRED  ALLEN,  F.C.S. 

Vol.  I.    Alcohols,  Ethers,  Vegetable  Acids   and   Fibers,  Starch 

and  its  Isomers,  etc.  Out  of  Print. 

Vol.  II.   Fixed  Oils  and  Fats,  Hydrocarbons  and  Mineral  Oils, 

Phenols  and  their  Derivatives,  Coloring  Matters,  etc.    Out  of  Print. 

Vol.  III. — Part  I.  Acid  Derivatives  of  Phenols,  Aromatic  Acids, 

Tannins,  Dyes,  and  Coloring  Matters.  Out  of  Print. 

Vol.  III. — Part  II.  The  Amins,  Pyridine  and  its  Hydrazins  and 

Derivatives,  the   Antipyretics,    etc.,  Vegetable   Alkaloids,  Tea, 

Coffee,  Cocoa,  etc.     8vo.  Cloth,  $4.50 

Vol.  III.— Part  III.  In  Press. 

HARTLEY.     Medical   and   Pharmaceutical  Chemistry. 

Fourth  Edition.  A  Text-book  for  Medical  and  Pharmaceutical 
Students.  By  E.  H.  BARTLEY,  M.D.,  Professor  of  Chemistry  and 
Toxicology  at  the  Long  Island  College  Hospital;  Dean  and  Pro- 
fessor of  Chemistry,  Brooklyn  College  of  Pharmacy;  President  of 
the  American  Society  of  Public  Analysts ;  Chief  Chemist,  Board 
of  Health,  of  Brooklyn,  N.  Y.  Revised  and  Enlarged.  92  Illus- 
trations, Glossary,  and  Complete  Index.  i2mo.  711  pages. 

Cloth,  $2.75;  Leather,  $3.25 

"  I  have  been  using  this  work  for  several  years,  and  have  during  the  same 
period  included  it  among  the  text-books  for  the  students  of  this  College.  . 
I  am  glad  to  note  the  enlargement  and  improvement  in  the  present  edition, 
especially  the  chapters  upon  New  Synthetical  Compounds  and  upon  Physiological 
and  Clinical  Chemistry,  and  am  sure  that  the  usefulness  and  popularity  of  the 
work  will  be  correspondingly  increased  thereby." — Dr.  Theo.  S.  Case,  Professor 
of  Chemistry,  Kansas  City,  Mo. 

BLOXAM.  Chemistry,  Inorganic  and  Organic.  With 
Experiments.  By  CHARLES  L.  BLOXAM.  Edited  and  Revised  by 
J.  M.  THOMPSON,  Professor  of  Chemistry  in  King's  College,  Lon- 
don, and  A.  G.  BLOXAM,  Head  of  Chemistry  Department,  The 
Goldsmith  Institute,  London.  Eighth  Edition.  Enlarged.  281  En- 
gravings, 20  of  which  are  new.  8vo.  Cloth,  $4.25  ;  Leather,  $5.25 

This,  the  eighth,  edition  of  "  Bloxani 's  Chemistry  "  has  been  very  thoroughly 
revised  and  as  far  as  possible  brought  up  to  date.  Many  changes  have  been  made, 
though  the  general  arrangement  remains  the  same.  The  sections  on  explosives,  to 
which  the  work  owes  considerable  reputation,  have  been  carefully  gone  over.  This 
is  a  standard  work  and  is  one  of  the  most  popular  text-books  now  issued.  It  is  in 
some  respects  more  thorough  and  complete  than  any  other  work. 


The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 

CALDWELL.  Chemical  Analysis.  Elements  of  Quali- 
tative and  Quantitative  Chemical  Analysis.  By  G.  C.  CALDWELL, 
B.S.,  PH.D.,  Professor  of  Agricultural  and  Analytical  Chemistry  in 
Cornell  University,  Ithaca,  New  York,  etc.  Third  Edition.  Re- 
vised and  Enlarged.  Octavo.  Cloth,  $1.50 

This  book  has  been  extensively  used  in  American  Schools  and  Colleges,  and 
needs  no  special  introduction.  Written  to  supply  Prof.  Caldwell's  need  in  his 
own  work,  it  is  an  eminently  practical  and  complete  text-book. 

Copies  sent  for  Examination,  $1.20,  postpaid. 

CLOWES  AND  COLEMAN.  Elementary  Qualitative 
Analysis.  Adapted  for  Use  in  the  Laboratories  of  Schools  and 
Colleges.  By  FRANK  CLOWES,  D.SC.,  Prof,  of  Chemistry,  and 
J.  BERNARD  COLEMAN,  Dem.  of  Chemistry,  University  College, 
Nottingham,  England.  Illustrated.  Cloth,  $1.00 

HOLLAND.  The  Urine,  the  Gastric  Contents,  the 
Common  Poisons,  and  the  Milk.  Memoranda,  Chemical  and 
Microscopical,  for  Laboratory  Use.  By  J.  W.  HOLLAND,  M.D., 
Professor  of  Medical  Chemistry  and  Toxicology  in  Jefferson  Med- 
ical College,  Philadelphia.  Fifth  Edition,  Enlarged.  Illustrated 
and  Interleaved.  i2mo.  Cloth,  $1.25 

"This  manual  deserves  to  be  generally  adopted  in  medical  schools  and  by 
physicians. " — Science, 

"  Dr.  Holland's  book  seems  to  contain  nearly  everything  that  could  be  desired 
without  covering  many  pages.  .  .  .  Altogether  we  can  recommend  this  book." 
—  University  Medical  Magazine ',  Philadelphia. 

LEFFMANN.  Compend  of  Medical  Chemistry,  Inor- 
ganic and  Organic.  Including  Urine  Analysis,  Chemistry  of  Tissues 
and  Secretions,  Table  of  Symbols,  Valencies,  Atomic  Weights,  etc. 
By  HENRY  LEFFMANN,  M.D.,  Prof,  of  Chemistry  and  Metallurgy  in 
the  Pennsylvania  College  of  Dental  Surgery  and  in  the  Wagner  Free 
Institute  of  Science,  Philadelphia;  Hygienist  and  Food  Inspector 
Pennsylvania  State  Board  of  Agriculture,  etc.  Fourth  Edition. 
Cloth,  .80.  Interleaved  for  the  addition  of  Notes,  $1.25 

The  Coal-Tar  Colors,  with  Special  Reference  to  their 
Injurious  Qualities  and  the  Restrictions  of  their  Use.  A  Trans-, 
lation  of  Theodore  Weyl's  Monograph.  121110.  Cloth,  $1.25 

Progressive    Exercises    in    Practical    Chemistry.       A 

Laboratory  Handbook.  Illustrated.  Second  Edition,  Revised 
and  Enlarged.  i2mo.  Cloth,  $1.00 

*#*  See  also  Water  and  Milk  Analysis,  page  lo. 

The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 


MUTER.      Practical    and    Analytical    Chemistry.      By 

JOHN  MUTER, F.R.S.,  F.C.S.,  etc.  Fourth  Edition.  Revised,  to  meet 
the  requirements  of  American  Medical,  Pharmaceutical,  and  Dental 
Colleges,  by  CLAUDE  C.  HAMILTON,  M.D.,  Professor  of  Analytical 
Chemistry  in  University  Medical  College  and  Kansas  City  College 
of  Pharmacy.  51  Illustrations.  Cloth,  $1.25 

"I  find  your  Milter's  Analytical  Chemistry  giving  great  satisfaction  in  my 
classes  in  chemical  analysis." — Prof.  Chas.  E.  Dickerson,  Jr.,  Director  Silliman 
Laboratory,  Mount  Herman  School,  Mount  Herman,  Mass. 

"  Milter's  Manual  of  Analytical  Chemistry,  several  previous  editions  of  which 
we  have  noticed,  now  appears  revised  in  an  American  edition  by  Dr.  Claude  C. 
Hamilton.  This  Revision  is  based  upon  the  fourth  English  edition.  The  editor 
has  made  only  such  changes  as  were  required  to  adapt  the  book  to  the  U.  S.  Phar- 
macopoeia, except  in  the  chapter  on  urine  analysis,  which  has  been  enlarged  and  to 
which  cuts  of  microscopic  sediments  and  other  illustrations  have  been  added.  The 
chapter  on  water  analysis  has  been  altered  to  correspond  with  Wanklyn's  methods, 
as  they  are  most  generally  used  in  America.  Several  other  processes  have  been 
added,  such  as  estimation  of  chloral  hydrate,  of  fat  in  milk,  etc.,  and  various 
minor  changes  in  arrangement  have  been  made  in  the  interest  of  convenience  in 
using  the  treatise." — The  Popular  Science  Monthly. 

VAN  NUYS  on  The  Urine.  Chemical  Analysis  of  Healthy 
and  Diseased  Urine,  Qualitative  and  Quantitative.  By  T.  C.  VAN 
NUYS,  Professor  of  Chemistry,  Indiana  University.  39  Illustrations. 
Octavo.  Cloth,  $1.00 

TYSON.     Guide  to  the  Practical  Examination  of  Urine. 

Ninth  Edition.  By  JAMES  TYSON,  M.D.,  Professor  of  Clinical 
Medicine,  University  of  Pennsylvania.  With  Colored  Plate  and 
48  Illustrations.  Ninth  Edition.  i2tno.  276  pages.  Cloth,  $1.25 

SMITH.  Electro-Chemical  Analysis.  By  EDGAR  F.  SMITH, 
Professor  of  Chemistry,  University  of  Pennsylvania.  Second 
Edition.  Enlarged.  28  Illustrations.  i2mo.  Cloth,  $1.25 

•\*  This  book  has  recently  been  translated  into  German  by  Dr.  Max  Ebeling 
of  Berlin,  and  published  by  Weidmann  of  the  same  city. 

"  The  greatest  advantage  of  the  electrolytic  method  of  analysis  is  its  sim- 
plicity. We  do  not  require  to  introduce  materials  the  purity  of  which  often  leaves 
something  to  be  desired,  and  which  have  to  be  again  removed,  frequently  at  the 
cost  of  much  time  and  trouble.  Hence,  where  available,  the  electrolytic  method 
of  analysis  possesses  an  indisputable  advantage.  We  hope  that  Prof.  Smith's 
little  work  will  call  increased  attention  to  this  branch  of  mineral  analysis." — 
Chemical  News,  London. 

"  Dr.  Smith  has  given  a  great  deal  of  study  to  this  branch  of  chemical 
analysis,  and,  as  might  have  been  expected,  he  has  produced  a  thoroughly  good 
book." — The  Journal  of  Analytical  Chemistry,  Easton,  Pa. 

"  Chemists  will  find  this  little  book  an  excellent  guide  to  a  knowledge  of  the 
methods  of  quantitative  analysis  by  electrolysis." — American  Chemical  Journal, 
Baltimore,  Md. 


The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 


SMITH  AND  KELLER.  Experiments.  Arranged  for 
Students  in  General  Chemistry.  By  EDGAR  F.  SMITH,  Professor  of 
Chemistry,  University  of  Pennsylvania,  Translator  of  Richter's 
Chemistries,  etc.,  and  Dr.  H.  F.  KELLER,  Professor  of  Chemistry, 
Philadelphia  High  School.  Third  Edition.  41  Illus.  Cloth,  .60 
"This  series  of  exercises,  based  on  the  authors'  experiences  with  their  own 
classes,  is  intended  to  accompany  any  convenient  text-book  of  inorganic  chemistry ; 
but  reference  is  made  to  that  of  Richter.  Beginning  with  fundamental  operations 
(as  with  blowpipe,  glass  tubing,  balance,  and  graduates)  and  general  principles 
(as  the  difference  between  chemical  and  physical  change),  the  course  proceeds  to 
the  study  of  hydrogen  and  other  non-metals  in  Part  I,  followed  by  the  metals  in 
Part  II.  Quantitative  relations  are  well  presented  in  the  experimental  work  and 
stoichiometrical  problems,  as  in  determining  the  .//-equivalent  of  zinc,  the  density 
of  Cl,  eudiometric  combustion  of  methane,  etc." — Science. 

STAMMER.  Chemical  Problems.  By  KARL  STAMMER. 
Translated,  with  Answers  added,  by  Prof.  W.  S.  HOSKINSON,  A.M., 
Wittenberg  College,  Springfield,  O.  i2mo.  Cloth,  .50 

"  An  excellent  practical  work,  just  what  every  thorough  teacher  of 
chemistry  needs."—  The  New  York  Teacher. 

SUTTON.  Volumetric  Analysis,  a  Systematic  Handbook 
of;  or,  the  Quantitative  Estimation  of  Chemical  Substances  by 
Measure,  applied  to  Liquids,  Solids,  and  Gases.  Adapted  to  the 
requirements  of  Pure  Chemical  Research,  Pathological  Chemistry, 
Pharmacy,  Metallurgy,  Manufacturing  Chemistry,  Photography, 
etc.,  and  for  the  Valuation  of  Substances  used  in  Commerce,  Agri- 
culture, and  the  Arts.  By  FRANCIS  SUTTON,  F.C.S.,  F.I.C.,  Public 
Analyst  for  the  County  of  Norfolk.  Seventh  Edition.  Revised  and 
Improved.  102  Illustrations.  In  Press. 

SYMONDS.  Manual  of  Chemistry,  for  Medical  Students. 
By  BRANDRETH  SYMONDS,  A.M.,  M.D.,  Ass't  Physician  Roosevelt 
Hospital,  Out-Patient  Department;  Attending  Physician  North- 
western Dispensary,  New  York.  Second  Edition.  Cloth,  $2.00 

TRIMBLE.  Practical  and  Analytical  Chemistry.  Being 
a  complete  course  in  Chemical  Analysis.  By  HENRY  TRIMBLE, 
PH.M.,  Professor  of  Analytical  Chemistry  in  the  Philadelphia  College 
of  Pharmacy.  Fourth  Edition.  Illustrated.  8vo.  Cloth,  $1.50 

WATTS'  Inorganic  Chemistry.     (Being  the  Fourteenth  Edi- 
tion of  FOWNE'S  INORGANIC  CHEMISTRY.)    By  HENRY  WATTS,  B.A., 
F.R.S.     Plate  of  Spectra  and  Illustrations.      12010.         Cloth,  $2.00 
Organic  Chemistry.     Second  Edition.     By  WM.  A.  TILDEN, 
D.SC.,  F.R.S.    (Being  the  Thirteenth  Edition  of  FOWNE'S  ORGANIC 
CHEMISTRY.)     Illustrated.     i2mo.  Cloth,  $2.00 

The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 


WOODY.     Essentials  of  Chemistry  and  Urinalysis.     By 

SAM  E.  WOODY,  A.M.,  M.D.,  Professor  of  Chemistry  and  Public 
Hygiene,  and  Clinical  Lecturer  on  Diseases  of  Children,  in  the 
Kentucky  School  of  Medicine.  Fourth  Edition.  Revised  with 
Tables  and  Illustrations.  1 2mo.  Nearly  Ready. 

"  The  fact  that  Prof.  Woody's  little  book  has  reached  a  third  edition  in  such 
a  short  time  is  sufficient  proof  of  its  usefulness  for,  and  demand  by,  the  medical 
student.  The  selection  of  the  material  and  its  plan  of  presentation  resulting  from 
the  author's  large  experience  as  a  practitioner  and  teacher  of  medical  chemistry  is 
well  intended  to  offer  to  the  student  that  which  is  really  essential  for  his  limited 
college  course,  and,  it  is  to  be  hoped,  a  basis  for  future  instruction  in  the  important 
branch  of  medical  science." — American  Journal  of  Medical  Science. 


TOXICOLOGY. 

REESE'S    Medical  Jurisprudence  and   Toxicology.     A 

Text-book  for  Medical  and  Legal  Practitioners  and  Students.  By 
JOHN  J.  REESE,  M.D.,  late  Professor  of  the  Principles  and  Practice 
of  Medical  Jurisprudence,  including  Toxicology,  in  the  University 
of  Pennsylvania,  Medical  Department.  Fourth  Edition.  Revised 
by  HENRY  LEFFMANN,  M.D.,  Pathological  Chemist,  Jefferson  Medi- 
cal College  Hospital,  Philadelphia;  Hygienist  and  Food  Inspector 
Pennsylvania  State  Board  of  Agriculture,  etc.  i2mo.  624  pages. 

Cloth,  $3.00;   Leather,  $3.50 

"  To  the  student  of  medical  jurisprudence  and  toxicology  it  is  invaluable,  as 
it  is  concise,  clear,  and  thorough  in  every  respect." — The  American  Journal  of 
the  Medical  Sciences. 

"The  book  happily  meets  the  needs  of  students,  and  we  unqualifiedly  com- 
mend it." — American  Practitioner  and  News,  Louisville. 

"  The  book  will  be  found  to  be  a  useful  one,  and  as  such  we  commend  it  to 
students  of  law  and  medicine." — Marshall  D.  Ewell,  Dean  of  the  Kent  Law 
School,  Chicago. 

TANNER'S  Memoranda  of  Poisons  and  their  Antidotes 
and  Tests.  By  THOS.  HAWKES  TANNER,  M.D.,  F.R.C.P.  Seventh 
American,  from  the  last  London  Edition.  Revised  by  JOHN  J. 
REESE,  M.D.,  Professor  of  Medical  Jurisprudence  and  Toxicology 
in  the  University  of  Pennsylvania.  1 2mo.  Cloth,  .  75 

"  The  fact  of  any  technical  work,  great  or  small,  reaching  its  seventh  edition 
speaks  for  itself.  In  the  most  condensed  form  are  given  the  history  of  poisons, 
their  antidotes,  and  various  mechanical  methods  for  overcoming  the  tendency  toward 
death.  The  principal  changes  in  the  new  edition  have  been  the  substitution  of 
modern  chemical  nomenclature  and  the  omission  of  obsolete  portions  of  the  old 
text.  The  toxicology  of  poisonous  food  has  been  presented  as  fully  as  the  concise 
character  of  the  book  allows." — Medical  Record,  New  York. 


The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


TECHNOLOGICAL  BOOKS. 

GROVES  AND   THORP.     Chemical  Technology.     The 

Application  of  Chemistry  to  the  Arts  and  Manufactures.  Edited 
by  CHARLES  E.  GROVES,  F.R.S.,  and  WM.  THORP,  B.SC.,  F.I.C.  In 
about  eight  octavo  volumes,  with  numerous  Illustrations.  Each 
volume  sold  separately.  See  Page  2  of  this  Catalogue. 

Vol.  I.  Fuel  and  Its  Applications.  By  Dr.  E.  J.  MILLS, 
F.R.S.,  Professor  of  Chemistry,  Anderson  College,  Glasgow;  and 
Mr.  F.  J.  ROWAN,  C.E.,  assisted  by  an  American  expert.  607 
Illustrations  and  4  Plates.  Cloth,  $5.00;  Half  Morocco,  $6.50 

"It  is  without  doubt  the  most  useful  and  comprehensive  book  in  the  English 
language  on  fuels,  and  is  a  valuable  acquisition  to  our  standard  books  of  refer- 
ence."— Journal  of  the  Franklin  Institute. 

"  It  covers  a  wide  range  of  knowledge,  and  should  be  at  the  elbow  of  every 
intelligent  and  progressive  manufacturer. " — The  Iron  Trade  Review,  Cleveland. 

"  The  book  will  be  very  useful  for  reference,  and  should  be  of  especial  value 
to  the  inventors  and  experimenters  or  users  of  processes  or  appliances  for  the  com- 
bustion of  fuels,  since  in  it  can  be  found  a  record  of  a  large  part  of  the  methods 
heretofore  proposed  and  adopted.  Where  critical  remarks  are  made  they  appear  to 
be  judicious.  The  illustrations  are  very  numerous  and  are  well  selected.  An 
immense  amount  of  information  has  been  crowded  into  these  closely  printed  802 
pages." — Engineering  and  Mining  Journal,  New  York. 

"The  book  is  very  fully  illustrated,  as,  indeed,  the  nature  of  the  subject 
requires,  and  includes  a  large  number  of  tables  giving  fuel  statistics,  analyses  of 
different  fuels,  and  comparative  results." — The  Railroad  and  Engineering  Journal. 

Vol.  II.  Lighting.  By  W.  Y.  DENT,  I.  MCARTHUR,  L.  FIELD, 
F.  A.  FIELD,  BOVERTON  REDWOOD,  and  D.  A.  Louis.  358  Illus- 
trations. Octavo.  Just  Ready. 

Cloth,  $4.00;  Half  Morocco,  $5.50 
Vol.  III.   Lighting — Continued.  In  Press. 

*q*  Descriptive  Circtilar,  List  of  Illustrations,  etc.,  free  upon  application. 

GARDNER.  The  Brewer,  Distiller,  and  Wine  Manu- 
facturer. Giving  full  Directions  for  the  Manufacture  of  Beers, 
Spirits,  Wines,  Liquors,  etc.,  etc.  A  Handbook  for  all  interested 
in  the  manufacture  and  sale  of  Alcohol  and  Its  Compounds.  Edited 
by  JOHN  GARDNER,  F.C.S.,  Editor  of  "  Cooley's  Cyclopedia"  and 
".Beasley's  Druggists'  Receipt  Book."  Illustrated.  Cloth,  $1.50 

"  Trustworthy  and  valuable." — German  and  American  Brezveri  Journal. 

"  A  very  complete  handbook." — Boston  Journal  of  Chemistry. 

Bleaching,  Dyeing,  and  Calico  Printing.  With  Formulae ; 
a  Chapter  on  Dye  Stuffs.  Illustrated.  i2mo.  Cloth,  #1.50 

"  A  serviceable  manual." — Inventors''  and  Manufacturers'  Gazette. 
"Worthy  the  confidence  of  the  large  class  of  workmen  for  whom  it  is  in- 
tended."—  Textile  Record. 

The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


BOOKS  FOR  CHEMISTS  AND  MANUFACTURERS. 


CAMERON.  Oils  and  Varnishes.  A  Practical  Handbook, 
by  JAMES  CAMERON,  F.I.C.  With  Illustrations,  Formula,  Tables, 
etc.  i2mo.  Cloth,  $2.25 

Soap  and  Candles.     A   New  Handbook   for   Manufacturers, 
Chemists,  Analysts,  etc.     54  Illustrations.      i2mo.     Cloth,  $2.00 

"  The  subject  is  thoroughly  treated  and  the  work  will  be  of  value  to  students 
and  all  others  interested  in  this  branch  of  manufactures." — Popular  Science  News , 
Boston. 

"The  book  shows  the  results  of  wide  reading  and  of  careful  collection  of 
data.  .  .  .  We  can  recommend  it  to  any  one  interested  in  the  manufacture  of 
soap  or  of  candles  as  a  work  that  will  prove  most  useful  to  him." — The  Journal 
of  the  Franklin  Institute. 

OVERMAN'S  Practical  Mineralogy,  Assaying,  and  Min- 
ing, with  a  Description  of  the  Useful  Minerals,  etc.  By  FREDERICK 
OVERMAN,  Mining  Engineer.  Eleventh  Edition.  Cloth,  $1.00 


WATER  AND  MILK  ANALYSES. 

LEFFMANN.  Examination  of  Water  for  Sanitary  and 
Technical  Purposes.  Presenting  those  Processes  that  are  Most  Trust- 
worthy and  Practical.  By  HENRY  LEFFMANN,  M.D.,  Professor  of 
Chemistry  and  Metallurgy,  Pennsylvania  College  of  Dental  Sur- 
gery, Hygienist  and  Food  Inspector  Pennsylvania  State  Board  of 
Agriculture,  etc.  Third  Edition.  Revised  and  Enlarged.  Illus- 
trated. i2mo.  Cloth,  $1.25 

"This  is  a  well  compiled  and  useful  little  treatise." — London  Lancet. 

"  An  admirable  digest  of  our  present  knowledge." — Journal  of  Analytical 
Chemistry. 

"  It  gives  all  the  standard  methods  for  determining  the  constituents  of  water, 
together  with  a  particularly  valuable  chapter  giving,  in  brief,  the  biological  exami- 
nation with  determination  of  colonies  of  bacteria." — Scientific  American. 

"  Especially  valuable  is  the  section  on  interpretation  of  results." — Railroad 
and  Engineering  News. 

BY    THE    SAME    AUTHOR. 

Analysis  of  Milk  and  Milk  Products.  Arranged  to  suit 
the  needs  of  Analytical  Chemists,  Dairymen,  and  Milk  Inspectors. 
i2mo.  Cloth,  $1.25 

"The  book  is  one  which  will  be  useful  in  the  hand  of  the  dairyman,  as  well 
as  in  the  hands  of  those  whose  duty  it  is  to  see  that  he  deals  fairly  with  his  cus- 
tomers."— London  Sanitary  Record. 

The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


MICROSCOPICAL   BOOKS. 

CARPENTER.  The  Microscope  and  Its  Revelations.  By 

W.  B.  CARPENTER,  M.D.,  F.R.S.  Seventh  Edition.  By  Rev.  DR. 
DALLINGER,  F.R.S.  Revised  and  Enlarged,  with  800  Illustrations 
and  21  Lithographs.  Octavo,  noo  pages.  Cloth,  $5.50 

"  The  book,  therefore,  cannot  fail  to  be  of  value  to  chemists  and  others  at 
iron  works  intrusted  with  the  microscopical  examination  of  the  metals  with  which 
they  deal." — The  American  Manufacturer,  Pittsburgh. 

"  Every  one  who  has  a  microscope  will  need  also  Carpenter's  book  to  get  the 
most  out  of  his  instrument,  and  every  one  who  has  the  book  will  be  certain  to  want 
a  microscope." — Popular  Science  Monthly. 

"It  is  without  a  rival  in  its  particular  field,  and  is  beyond  question  the  best 
single  work  on  the  subject,  not  only  in  English  but  in  any  other  language.  .  .  . 
A  splendid  specimen  of  the  book-maker's  art." 

"  The  book  is  more  than  ever  a  standard,  unrivaled  in  its  kind,  and  is  a  neces- 
sity to  every  one  who  pretends  to  any  scientific  use  of  the  microscope." — New  York 
Evening  Post. 

WETHERED.  Medical  Microscopy.  By  FRANK  J.  WETH- 
ERED,  M.D.,  M.R.C.P.  With  ioo  Illustrations.  i2mo. 

Cloth,  $2.00 

REEVES.  Medical  Microscopy.  Including  chapters  on 
Bacteriology,  Neoplasms,  Urinary  Examination,  etc.  By  JAMES  E. 
REEVES,  M.D.,  Ex-President  American  Public  Health  Association, 
etc.  Illustrated.  121110.  Cloth,  $2.50 


THE  BEST  DICTIONARY. 

GOULD.  Illustrated  Dictionary  of  Medicine  and  Allied 
Sciences,  including  Chemistry,  Biology  (Zoology  and 
Botany),  Hygiene,  etc.  Large,  Square  Octavo.  1633  pages. 

Half  Morocco,  )   ..  ,,,..,,   r~,       ,   T 

-p  J,  c,  '  v$io.oo.     With  Thumb  Index,  $n.oo 

Half  Russia,  Thumb  Index,  $12.00 

*#*  There  being  no  special  dictionaries  devoted  to  Chemistry  and  Biology, 
it  was  thought  eminently  proper  to  include  both  these  sciences  in  this  book.  They 
are  closely  related  to  medicine,  and  each  is  largely  dependent  upon  the  others. 
Gould's  Illustrated  Dictionary  contains  much  special  information  of  practical  use  to 
the  general  scientist.  Bacteriology  and  Parasitology  are  particularly  well  pre- 
sented, while  the  numerous  tables  of  Acids,  Alcohols,  Aldehyds,  Carbohydrates, 
Electric  Units,  Ethers,  Foods,  Hydrocarbons,  Laws,  Milks,  Oils,  Pigments,  Pto- 
mains,  Resins,  Soaps,  Stains,  Starches,  Sugars,  Tests,  Theories,  Wave  Lengths, 
Weights  and  Measures,  etc.,  will  be  found  unique  and  exceedingly  valuable. 

Jgjg*'  Handsome  descriptive  circular,  with  sample  pages  and  illustrations,  will 
be  sent  free  upon  application. 

The  prices  of  these  books  are  net.    No  discount  allowed  retail  purchasers. 


HYGIENE  AND  SANITARY  SCIENCE. 

COPLIN    AND    BEVAN.     Practical    Hygiene.      By  W. 

M.  L.  COPLIN,  M.D.,  Adjunct  Professor  of  Hygiene,  and  D.  BEVAN, 
M.D.,  Ass't  Department  of  Hygiene,  Jefferson  Medical  College, 
Philadelphia;  Bacteriologist,  St.  Agnes'  Hospital,  with  an  introduc- 
tion by  Prof.  H.  A.  HARE,  and  articles  on  Plumbing,  Ventilation, 
etc.,  by  Mr.  W.  P.  Lockington.  138  Illustrations,  some  of  which 
are  in  colors.  8vo.  Cloth,  $4.00 

TABLE  OF  CONTENTS. 


Introduction. 

Chapter  I.  Hygiene— Health— Cause  and 
Prevention  of  Disease. 

II.  Individual  or  Personal  Hy- 

giene. 

III.  Clothing. 

"        IV.    Food  — Examination    of 

Meats,  Liquors,  etc. 
"        V.  Water— Its  Sources,  Storage, 
Distribution,  Purification, 


VI.  Air. 


Analysis,  etc. 


Chapter  VII.  Climate. 

VIII.  Soil. 

"        IX.  Habitations. 
"        X.  Sewage— Its  Disposal,  etc. 
"        XI.  Disposal  of  the  Dead. 
"        XII.  Technic— Methods  of  Col- 
lecting,   Preserving,   and 
Handling    Specimens, 
Staining,   Necessary  Ap- 


Appendix. 
Index. 


paratus,  etc. 


The  many  special  subjects  considered  in  this  volume  demanded  much  expert 
knowledge ;  in  order,  therefore,  that  the  statements  made  should  be  accurate,  the 
authors  have  consulted  with  and  received  valuable  help  from  various  specialists 
in  Architecture,  Food  Analysis,  Chemistry,  Heating,  Ventilation,  etc. 

STEVENSON  AND  MURPHY.  A  Treatise  on  Hy- 
giene. Illustrated.  Edited  by  THOMAS  STEVENSON,  M.D.,  F.R.C. P., 
Lecturer  on  Chemistry  and  on  Medical  Jurisprudence  at  Guy's  Hos- 
pital, Official  Analyst  to  the  Home  Office;  and  SHIRLEY  F.  MUR- 
PHY, Medical  Officer  of  Health  to  the  County  of  London. 

Vol.  I.  9  Plates.  186  Illustrations.  1013  pages.  Cloth,  $6.00 
Vol.  II.  45  Plates.  31  Illustrations.  847  pages.  Cloth,  $6.00 
Vol.  III.  Sanitary  Law.  459  pages.  Cloth,  $5.00 

EACH  VOLUME  SOLD  SEPARATELY. 

"  The  different  topics  are  fully  and  intelligently  treated,  especially  those 
which  relate  to  the  subjects  of  Ventilation,  Water,  Soil,  Food,  Physical  Education, 
the  Dwelling,  and  the  Disposal  of  Refuse.  The  work  is  fully  illustrated  with 
plates,  diagrams,  and  wood-cuts,  and  pains  appear  to  have  been  taken  to  bring  the 
information  upon  each  topic  up  to  date." — The  Boston  Medical  and  Surgical 
Journal, 

"  All  the  topics  are  treated  with  a  thoroughness  of  detail  leaving  nothing  to 
be  desired.  The  contents  are  valuable  alike  to  the  physician,  the  municipal  health 
officer,  and  the  sanitary  engineer." — Medical  Record,  New  York. 

"The  additions  which  during  recent  years  have  been  made  to  our  knowledge 
of  preventive  medicines  and  of  the  conditions  which  affect  health  demand  larger 
treatment  than  can  be  given  in  a  handbook.  The  suggestion  made  by  the  late 
Professor  de  Chaumont,  that  a  treatise  should  be  issued  containing  essays  by  vari- 
ous authors,  was  therefore  well  worthy  of  adoption,  for  it  is  obvious  that  special 
knowledge  is  required  for  the  discussion^f-rasfeoijtygj^gv^ral^ subjects  which  come 
within  the  scope  of  such  a  work." — 

\*  For  complete  list  of  books  on  Hygiene,  send  for  our  Special  Catalogue. 

THE  PRICES  OF  THESE  BOOKS  ARE  NET. 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 

THIS  BOOK  IS  DUE  ON  THE  LAST  DA 
STAMPED  BELOW 


TE 


151915 


0  5 1996 


FEB 

CIR 


30m-l/15 


YB   !687o 


U.  C.  BERKELEY  LIBRARIES 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


